A security guard walks inside the top of the Shanghai Tower, during heavy rain at the financial district of Pudong in Shanghai May 15, 2015. The Shanghai Tower stands at approximately 632 metres (2,073 ft) and will be the tallest skyscraper in China and the second tallest in the world when it is completed in the summer of 2015. (Photo by Aly Song/Reuters)

Skyscrapers Shanghai World Financial Center (R) and Jin Mao Tower are seen during heavy rain at the financial district of Pudong in Shanghai May 15, 2015. (Photo by Aly Song/Reuters)

Worker work inside the Shanghai Tower, at the financial district of Pudong in Shanghai May 15, 2015. (Photo by Aly Song/Reuters)

Residents observe as policemen take up position near an area where two men were found dead on top of the Sao Carlos slums complex in Rio de Janeiro May 15, 2015. According to residents of the complex, there is an ongoing war between drug dealers in the region and these two men were killed by the police during a police operation in the same area the previous night. Police told local media that they will investigate the deaths. (Photo by Ricardo Moraes/Reuters)

Residents shout at a Special Operations Battalion (BOPE) Police officer after the bodies of two men were found in the Sao Carlos slum complex in Rio de Janeiro, Brazil, Friday, May 15, 2015. (Photo by Ricardo Moraes/Reuters)

Lebanon's Hezbollah fighters rest on the back of a pick-up truck with an installed weapon in Khashaat, in the Qalamoun region after they advanced in the area May 15, 2015. Lebanon's Hezbollah and Syria's army made big advances against insurgents in mountains north of Damascus on Wednesday, Hezbollah and Syrian state media said, shoring up President Bashar al-Assad's grip on the border zone. (Photo by Mohamed Azakir/Reuters)

Pope Francis arrives for an audience with a group of children in the Paul VI hall at the Vatican, Monday, May 11, 2015. (Photo by L'Osservatore Romano/AP Photo/Pool Photo)

A supporter of Gen. Draza Mihajlovic, a World War II royalist guerrilla commander, holds a photo of Vladimir Putin, the Russian president, as he stands in front of the Higher Court in Belgrade, Serbia, Thursday, May 14, 2015. A Belgrade court on Thursday quashed the treason conviction of Mihailovic for his collaboration with Nazis during World War II, politically rehabilitating the controversial Serbian guerrilla commander almost 70 years after he was sentenced and shot to death by communists. (Photo by Marko Drobnjakovic/AP Photo)

A demonstrator carries and inflatable doll as police blocks the street to prevent demonstrators marking Teacher's Day from approaching the Zocalo plaza in Mexico City, Friday, May 15, 2015. Demonstrators protested against the education reform and the governments' handling of the disappearance of 43 rural teachers' college students in southern Mexico last year. (Photo by Marco Ugarte/AP Photo)

In this Friday, May 8, 2015 photo, cars drive past the communist-era Palace of Culture in Warsaw, Poland. The Warsaw Experience tour offered by the Charm of PRL museum gives visitors a peek at life under Poland's bygone communist system with a visit to a tiny apartment, a taste of cherry vodka and a ride in a militia van. (Photo by Czarek Sokolowski/AP Photo)

In this Friday, May 8, 2015 photo, tourists visit the museum of communism in Warsaw, Poland. (Photo by Alik Keplicz/AP Photo)

In this Friday, May 8, 2015 photo, a communist-era sitting room is presented in the Charm of PRL museum in Warsaw, Poland. (Photo by Alik Keplicz/AP Photo)

In this April 28, 2015 photo, communist-era Polish made Nysa vans appear on display in front of a wall with old neon store names near the Charm of PRL museum in Warsaw, Poland. (Photo by Czarek Sokolowski/AP Photo)

A Pakistani lawyer holds a candle during a vigil for the victims of the Gilgit helicopter crash, in Lahore, Pakistan 11 May 2015. The ambassadors of Norway and the Phillipines were killed along with the spouses of the Indonesian and Malaysian envoys and three crew members when a helicopter crashed 08 May in the northern region of Gilgit-Baltistan, their bodies have been recovered from the crash site to be brought to Islamabad 09 May. (Photo by Rahat/Dar/EPA)

A view of “Les Belles Danses” (The beautiful dances) by French artist Jean-Michel Othoniel, one of the three fountain sculptures installed at the Water Theatre Grove in Versailles outside Paris, France, Tuesday, May 12, 2015. Designed by Andre Le Notre between 1671 and 1674, this grove is located in the gardens of the Palace of Versailles. Following an international competition aimed at garden designers for the restoration of the Water Theatre grove, the landscape designer Louis Benech and the artist Jean-Michel Othoniel were chosen for their contemporary art project. (Photo by Christophe Ena/AP Photo)

Russians living in Greece hold banners calling the E.U. and the U.S. to stop supporting the Ukrainian government, during an annual ceremony marking the end World War II, at an Allied Forces cemetery at the northern port city of Thessaloniki, Greece, on Saturday, May 9, 2015. Every year on this date Serbian and Russian veterans attend the ceremony and laid wreaths in commemoration of their compatriots who got killed during the war. (Photo by Giannis Papanikos/AP Photo)

A bus burns after being set on fire by demonstrators in the Ngagara district of Bujumbura, Burundi Tuesday, May 12, 2015. A crowd who were marching to the funeral of a woman who died in recent protests were blocked from doing so by police, and the crowd then set fire to a bus and government car and motorcycle. (Photo by Berthier Mugiraneza/AP Photo)

Foody, background, left, the Expo mascot, is seen during the morning parade at the Expo 2015 in Rho, near Milan, Italy, Wednesday, May 13, 2015. The Expo 2015 world's fair opened Friday May 1 for a six-month run and its theme is “Feeding the Planet, Energy for Life”. (Photo by Luca Bruno/AP Photo)

Visitors look at the installation “Donna carota” (Carrot woman) by Italian artist Luigi Serafini, on display at the Expo 2015 in Rho, near Milan, Italy, Wednesday, May 13, 2015. (Photo by Luca Bruno/AP Photo)

In this photo taken on Tuesday, May 7, 2015, people take part in different type of sport moves, including push ups over dug out holes in the sand at Fann Beach in Dakar, Senegal. It isn't Venice Beach, it's Fann Beach, and the sounds of waves serves as a background rhythm for hundreds of super-fit, sport loving Senegalese who swarm to the beach en masse every day for a workout to chants and cheers. (Photo by Jane Hahn/AP Photo)

In this photo taken on Tuesday, May 7, 2015, Dioumayatou Ba, center, stretches during a class on Fann Beach in Dakar, Senegal. (Photo by Jane Hahn/AP Photo)

Tourists from India take part in a pillow fight in Ljubljana, Slovenia, May 14, 2015. The pillow fight is part of fundraising efforts for earthquake-affected victims in Nepal organized by a local radio station. (Photo by Srdjan Zivulovic/Reuters)

Visitors look at a robot serving for cards games at the 18th China Beijing International High-Tech Expo in Beijing, China, 13 May 2015. The expo runs from 13 to 17 May at the China International Exhibition Center displaying high-tech products coming from as many as 1,600 domestic and foreign enterprises. (Photo by Wu Hong/EPA)

US and Ukrainian soldiers take part in joint military exercises near the western Ukrainian city of Lviv, Ukraine, 14 May 2015. The Fearless Guardian – 2015 drill kicked off at the Yavoriv military base in western Ukraine, close to the border with Poland on 20 April 2015. Some 300 US soldiers from the 173rd Airborne Brigade Combat Team of the US Army are training Ukrainian National Guard soldiers as part of a long-term strategy for improving Ukrainian defence. (Photo by Ivan Boberskyy/EPA)

Smoke rises from a house of former Yemeni president Ali Abdullah Saleh after a Saudi-led airstrike in Sanaa, Yemen, Sunday, May 10, 2015. (Photo by Hani Mohammed/AP Photo)

Workers set up the official poster of the 68th annual Cannes Film Festival on the Palais des Festivals facade, in Cannes, France, 11 May 2015. The poster displays a photograph of Swedish actress Ingrid Bergman taken by Polish photographer David Seymour. The film festival will run from 13 to 24 May. (Photo by Guillaume Horcajuelo/EPA)

A baker shows how to make a “watermelon toast” at the Jimmy's Bakery in Jiaohsi Township, Yilan County, northern Taiwan, 11 May 2015. Lee Wen-fa, owner of the bakery, began making “watermelon toast” in April 2015 to make toast interesting to children as kids lose their appetite in summer when the weather gets hot. He uses tea powder, strawberry, bamboo charcoal and food dye to creat the green, red, dark and yellow colors in the toast. The bakery used to sell about 100 loafs of toast in the past, but is now selling 1,500 loafs of the “watermelon toast” and still cannot keep up with the orders which are coming in from all over the island. (Photo by David Chang/EPA)

Anderson Hernanes (R) of FC Internazionale Milano celebrates after scoring the team's first goal during the Serie A match between SS Lazio and FC Internazionale Milano at Stadio Olimpico on May 10, 2015 in Rome, Italy. (Photo by Paolo Bruno/Getty Images)

Two visitors look at the figure of a character, from the US-series “Game of Thrones”, a white walker, mirrored on the surface of a window, is on display during the openinig of the “Game of Thrones” exhibition in Berlin, Germany, 13 May 2015. The exhibition runs from 13 May to 17 May. (Photo by Jens Kalaene/EPA)

Cast members from the new Mad Max movie, “Mad Max – Fury Road”, film a promotion near the Sydney Opera House in Sydney, Australia, 13 May 2015. (Photo by Dean Lewins/EPA)

Diane Zolnercikova of the Czech Republic dives for a ball during Day 1 of the FIVB Lucerne Open on May 12, 2015 in Lucerne, Switzerland. (Photo by Jordan Mansfield/Getty Images for FIVB)

The waste robot “Reiner” drives through the Mauerpark and collects waste in Berlin, Germany, 14 May 2015. (Photo by Gregor Fischer/EPA)

Greek Orthodox believers pay their respects to the holy relics of St. Barbara, which came from Venice, outside the St. Savvas state cancer hospital in Athens, Greece, 15 May 2015. Hundreds of pilgrims have being waiting outside the Saint Savvas state cancer hospital in Athens for the arrival of the relics of Saint Barbara (Agia Varvara in Greek) forcing the police to divert traffic around the hospital. A silver casket, containing the holy relics of Saint Barbara, which has been kept in Venice for the last thousand years, came in Athens last Sunday and will remain in the Holy Pilgrimage until Sunday, May 24, 2015. (Photo by Yannis Kolesidis/EPA/)

Midwives and pregnant women show their painted breasts during a demonstration in Buenos Aires on May 14, 2015 against the scheduled new policy of the Healt Minister to regulate home natural births. The signs read “Yes to home birth”. (Photo by Juan Mabromata/AFP Photo)

Tyres are removed from the Mediterranean Sea on May 12, 2015 in Vallauris Golfe-Juan, southeastern France. 2,500 tyres used as artificial reefs have been removed these last days in this bay. About 25,000 had been immersed in the Mediterranean Sea between the cities of Cannes and Antibes in the 1980s. (Photo by Jean Christophe Magnenet/AFP Photo)

People arrive in their Cirtroen 2CVs during the 22nd National Meeting of French 2CV clubs in La Rochelle on May 13, 2015. (Photo by Xavier Leoty/AFP Photo)

Mahmoud el-Deeb, 77, left, plays music as he sits with his neighbor Ali Qarra, 75, right, while sitting at a traditional tent as they mark the Nakba Day in Zaneh, neighborhood east of Khan Younis, in the southern Gaza Strip, Friday, May 15, 2015. Palestinians marked the Nakba Day, or the Day of the Catastrophe, when hundreds of thousands of Palestinians were expelled from their towns during the first Israeli-Arab war in 1948. (Photo by Adel Hana/AP Photo)

Sage Erickson of the United States surfs during Round 1 Heats at the Oi Rio Pro on May 12, 2015 in Rio de Janeiro, Brazil. (Photo by Matthew Stockman/Getty Images)

Fans attempt to dodge the loose bat of Josh Donaldson #20 of the Toronto Blue Jays in the third inning against the Baltimore Orioles at Oriole Park at Camden Yards on May 12, 2015 in Baltimore, Maryland. (Photo by Patrick Smith/Getty Images)

Ishmael Bermudez blows into a conch shell he found in the backyard of his home that is mostly surrounded by high rise buildings and ongoing construction projects on May 13, 2015 in Miami, Florida. Bermudez has been excavating the backyard of his home for the last few decades and believes it is a mystical place, has a natural spring and where he says he has found evidence of the earliest inhabitants of the area. Developers have driven up the value of his property to at least $1.8 million, but Ishmael has no plans to sell unless his backyard can be protected. (Photo by Joe Raedle/Getty Images)

Marksmen in traditional Bavarian folk dress with salute guns fire their salute during the annual Ascension Mass (in German called Christi Himmelfahrt) at the open-air altar at Birkenstein on May 14, 2015 near Fischbachau, Germany. Several thousand pilgrims from 40 different folk group associations participated in the annual event to mark Jesus Christ's ascension to Heaven in a tradition going back centuries. Bavaria is predominantly Catholic. (Photo by Philipp Guelland/Getty Images)

Environmental activists protest the arrival of the Polar Pioneer, an oil drilling rig owned by Shell Oil, on May 14, 2015 in Seattle, Washington. The rig is part of a fleet that will lead a controversial oil-exploration effort off Alaska's North Slope. (Photo by Karen Ducey/Getty Images)

Rohingya migrants pass food supplies dropped by a Thai army helicopter to others aboard a boat drifting in Thai waters off the southern island of Koh Lipe in the Andaman sea on May 14, 2015. A boat crammed with scores of Rohingya migrants – including many young children – was found drifting in Thai waters on May 14, with passengers saying several people had died over the last few days. (Photo by Christophe Archambault/AFP Photo)

Rohingya migrants swim to collect food supplies dropped by a Thai army helicopter after they jumped from a boat (R) drifting in Thai waters off the southern island of Koh Lipe in the Andaman sea on May 14, 2015. (Photo by Christophe Archambault/AFP Photo)

A Rohingya girl sits on a bus as relocated to their new temporary shelter on May 13, 2015 in Lhoksukon, Aceh province, Indonesia. Boats carrying over 500 of Myanmar's Rohingya refugees have arrived in Indonesia, many requiring medical attention. They have warned that thousands more are thought to be still at sea. Myanmar's Rohingya Muslim community have long been persecuted and marginalized by Myanmar's mostly Buddhist population. (Photo by Ulet Ifansasti/Getty Images)

In this April 8, 2010 file photo, a US Airways plane takes off from Sky Harbor International Airport in Phoenix. American Airlines on Tuesday, May 12, 2015 said it plans to shut down the venerable carrier over a 90-day stretch that could begin as soon as July, which would mean a final departure around October. (Photo by Cheryl Evans/AP Photo/The Arizona Republic)

A man lies on the street covered with bricks on his back, during a performance against corruption, in Pamplona, northern Spain, Thursday, May 14, 2015, prior to the Regional Spanish Elections to be held on May 24. (Photo by /Alvaro Barrientos/AP Photo)

Members of staff makes last minute touch ups of wax figure Chewbacca, from Star Wars, on display at “Star Wars At Madame Tussauds” on May 12, 2015 in London, England. (Photo by Stuart C. Wilson/Getty Images)

Members of staff put the finishing touches to the wax figure of Star Wars character Chewbacca at the Star Wars At Madame Tussauds attraction in London on May 12, 2015. (Photo by Justin Tallis/AFP Photo)