A visitor takes in a view of the downtown district from Twin Peaks on Friday, January 9, 2015, in San Francisco. (Photo by Marcio Jose Sanchez/AP Photo)

A Tibetan man stirs butter tea made for the arriving guest during the function organised to mark Losar or the Tibetan New Year at a Tibetan Refugee Camp in Lalitpur February 19, 2015. Tibetans across the world marked the arrival of the New Year with prayers and festivities. (Photo by Niranjan Shrestha/AP Photo)

A female Syrian soldier from the Republican Guard commando battalion drives a tank during clashes with rebels in the restive Jobar area, in eastern Damascus, on March 25, 2015. The female battalion, which was created nearly a year ago, consists of 800 female soldiers who are positioned in the suburbs of the Syrian capital where they monitor and secure the frontlines with snipers, rockets and machine guns. (Photo by Joseph Eid/AFP Photo)

School girls stand next to a ballot box at a polling station during the municipal elections in Havana April 19, 2015. Cuba held its first local elections since a historic thaw in relations with the United States with an unusual wrinkle in the single-party system: two of the 27,000 candidates openly oppose the government. (Photo by Reuters/Stringer)

Potters colour earthen lamps at a workshop ahead of the Hindu festival of Diwali in Amritsar October 15, 2014. Earthen lamps are sold in large numbers during Diwali, the annual Hindu festival of lights, as people use them to decorate their homes. (Photo by Munish Sharma/Reuters)

Cast members Ryan Hansen, Kristen Bell, and Jason Dohring (L-R) pose at the premiere of “Veronica Mars” in Hollywood, California in this March 12, 2014 file photo. (Photo by Mario Anzuoni/Reuters)

A person dressed like a zombie walks during the 2015 Comic-Con International Convention in San Diego, California July 9, 2015. The pop-culture held at the San Diego Convention Center event runs July 9-12. (Photo by Mario Anzuoni/Reuters)

Festival-goers enjoy the mud during the annual Boryeong Mud Festival at Daecheon Beach on July 18, 2015 in Boryeong, South Korea. The mud, which is believed to have benefical effects on the skin due to its mineral content, is sourced from mud flats near Boryeong and transported to the beach by truck. (Photo by Chung Sung-Jun/Getty Images)