Indonesian motorists push their motorbikes as they wade through a flooded street outside the presidential palace in Jakarta, Indonesia, 09 February 2015. Incessant rain overnight triggered widespread flooding in the Indonesian capital Jakarta, bringing traffic to a standstill. The city hall in central Jakarta and the front lawn of the presidential palace were inundated in up to 20 centimetres of water, television pictures showed, after heavy rain. (Photo by Mast Irham/EPA)

People ride a prototype of a driverless vehicle as it is moves through a pedestrian area in Greenwich, east London, February 11, 2015. Britain has begun testing driverless cars in four cities, launching the first official trials ahead of a series of planned rule reviews to accommodate the new technology. (Photo by Suzanne Plunkett/Reuters)

An unmanned Falcon 9 SpaceX rocket lifts off from launch complex 40 at the Cape Canaveral Air Force Station, Wednesday, February 11, 2015, in Cape Canaveral, Fla. On board is the Deep Space Climate Observatory, which will head toward a solar-storm lookout point a million miles away. (Photo by John Raoux/AP Photo)

Sikh devotees participate in the Baisakhi festival at Panja Sahib shrine in Hassan Abdel April 13, 2015. Hundreds of Indian Sikh pilgrims arrived into Pakistan to celebrate the Baisakhi festival with Pakistani Sikhs at the shrines of Panja Sahib and Nankana Sahib, the birth place of Sikh faith founder Guru Nanak Dev. (Photo by Caren Firouz/Reuters)

People immerse themselves in an ice hole in the Chulym river, with the air temperature at about minus 12 degrees Celsius (10.4 degrees Fahrenheit), during celebrations for the Russian Orthodox Epiphany outside of the town of Nazarovo, Krasnoyarsk region January 19, 2015. (Photo by Ilya Naymushin/Reuters)

Women carry gas cylinders to fill them at a distribution point in Cairo January 19, 2015. Egypt is going through its worst energy crisis in decades and is seeking fresh sources of natural gas, which powers most of its homes and factories. (Photo by Mohamed Abd El Ghany/Reuters)

Villagers take part in Kolyada holiday celebrations in the village of Martsiyanauka, east of the capital Minsk, January 21, 2015. Local residents took part in the celebrations to mark the end of a pagan winter holiday Kolyada, which over the centuries has merged with Orthodox Christmas celebrations. (Photo by Vasily Fedosenko/Reuters)

A Sumatran Tiger looks at visiting children from it's enclosure during the ZSL London Zoo's annual stocktake of animals on January 5, 2015 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Dan Kitwood/Getty Images)