epa05386225 Police officers stand guard outside the courthouse before a verdict was issued in the trial of police officer Caesar Goodson, one of six Baltimore police officers charged over the death of Freddie Gray, in Baltimore, Maryland, USA, 23 June 2016. A judge issued a verdict of not-guilty in all accounts in the trial of Goodson.  EPA/MICHAEL REYNOLDS

Michael Reynolds/EPA

Police officers stand guard outside the courthouse before a verdict was issued in the trial of police officer Caesar Goodson, one of six Baltimore police officers charged over the death of Freddie Gray, in Baltimore, Maryland. A judge issued a verdict of not-guilty in all accounts in the trial of Goodson.

Jeff Lawson, (C) Founder, CEO, & Chairman of Communications software provider Twilio Inc., takes a selfie photo during his company's IPO on the floor of the New York Stock Exchange (NYSE) in New York City, U.S., June 23, 2016. REUTERS/Brendan McDermid

Brendan McDermid/Reuters

Jeff Lawson, (C) Founder, CEO, & Chairman of Communications software provider Twilio Inc., takes a selfie photo during his company’s IPO on the floor of the New York Stock Exchange (NYSE) in New York City

Protestors hold a smoke bomb and a placard of the French General Confederation of Labour (CGT) worker's union of the dockers branch during a demonstration against the French government's planned labour law reforms on June 23, 2016 in Marseille, southern France. Unions are protesting a series of labour market reforms that Valls had to force through parliament in May to avoid a vote, even after the bill was significantly watered down. However after more than three months of protests and strikes over the legislation, neither side is willing to budge. / AFP PHOTO / ANNE-CHRISTINE POUJOULATANNE-CHRISTINE POUJOULAT/AFP/Getty Images

Anne-Christine Poujoulat/AFP/Getty

Protestors hold a smoke bomb and a placard of the French General Confederation of Labour (CGT) worker’s union of the dockers branch during a demonstration against the French government’s planned labour law reforms in Marseille, France

Local residents cast their votes on the EU referendum at a polling staton at the East Hull Boxing Club in Kingston-Upon-Hull, northern England on June 23, 2016. Millions of Britons began voting today in a bitterly-fought, knife-edge referendum that could tear up the island nation's EU membership and spark the greatest emergency of the bloc's 60-year history. / AFP / Lindsey Parnaby        (Photo credit should read LINDSEY PARNABY/AFP/Getty Images)

Lindsey Parnaby/AFP/Getty

Local residents cast their votes on the EU referendum at a polling station at the East Hull Boxing Club in Kingston-Upon-Hull, northern England

Displaced children, who fled from Islamic State violence, and the needy receive free food distributed during the fasting month of Ramadan at a restaurant in Baghdad, Iraq, June 22, 2016. REUTERS/Ahmed Saad     TPX IMAGES OF THE DAY

Ahmed Saad/Reuters

Displaced children, who fled from Islamic State violence, and the needy receive free food distributed during the fasting month of Ramadan at a restaurant in Baghdad 

Indian pedestrians carry a dog as they make their way past others sheltering in a pavilion during a heavy monsoon rain downpour in Shimla on June 22, 2016.     At least 93 people have been struck by lightning and killed in India over the past two days, disaster management officials said, as annual monsoon rains swept the country. Lightning strikes are relatively common in India during the June-October monsoon, which hit the southern coast earlier this month, but this week's toll is particularly high.  / AFP PHOTO / STRSTR/AFP/Getty Images

AFP

Indian pedestrians carry a dog as they make their way past others sheltering in a pavilion during a heavy monsoon rain downpour in Shimla, India

Puerto Rico's Monica Puig celebrates winning against Denmark's Caroline Wozniacki (not in picture) during day three of the 2016 AEGON International at Devonshire Park, Eastbourne. PRESS ASSOCIATION Photo. Picture date: Wednesday June 22, 2016. See PA story TENNIS Eastbourne. Photo credit should read: Steve Paston/PA Wire. RESTRICTIONS: Editorial use only, No commercial use without prior permission, please contact PA Images for further information: Tel: +44 (0) 115 8447447.

Steve Paston/PA

Puerto Rico’s Monica Puig celebrates winning against Denmark’s Caroline Wozniacki during day three of the 2016 AEGON International at Devonshire Park, Eastbourne 

A "Vote Remain" banner being flown by an aircraft is seen behind the Big Ben clocktower in London, Britain June 22, 2016.  REUTERS/Toby Melville

Toby Melville/Reuters

A “Vote Remain” banner being flown by an aircraft is seen behind Big Ben in London 

epa05383038 Russian President Vladimir Putin (C) lays flowers during a wreath-laying ceremony in the Alexander Garden near the Kremlin wall in Moscow, Russia, 22 June 2016, to mark the 75th anniversary of the Nazi German invasion into the then Soviet Union territory on 22 June 1941.  EPA/GRIGORY DUKOR / POOL

Grigory Dukor/EPA

Russian President Vladimir Putin lays flowers during a wreath-laying ceremony in the Alexander Garden near the Kremlin wall in Moscow to mark the 75th anniversary of the Nazi German invasion into the then Soviet Union territory on 22 June 1941 

British Prime Minister David Cameron (C) addresses pro-EU "Vote Remain" supporters during a rally in Bristol, Britain June 22, 2016. REUTERS/Geoff Caddick/Pool

Geoff Caddick/Reuters

British Prime Minister David Cameron addresses pro-EU “Vote Remain” supporters during a rally in Bristol, England

Jun 21, 2016; Toronto, Ontario, CAN; Toronto Blue Jays center fielder Kevin Pillar (11) catches a fly ball for an out during the fourth inning in a game against the Arizona Diamondbacks  at Rogers Centre. Mandatory Credit: Nick Turchiaro-USA TODAY Sport

Nick Turchiaro/Reuters

Toronto Blue Jays center fielder Kevin Pillar (11) catches a fly ball for an out during the fourth inning in a game against the Arizona Diamondbacks at Rogers Centre, Toronto 

Bishops use umbrellas to protect themselves from the sun as Pope Francis leads his Wednesday general audience in Saint Peter's square at the Vatican June 22, 2016. REUTERS/Stefano Rellandini

Stefano Rellandini/Reuters

Bishops use umbrellas to protect themselves from the sun as Pope Francis leads his Wednesday general audience in Saint Peter’s square at the Vatican 

Lightning flashes during a thunderstorm over Havana, Cuba June 21, 2016. REUTERS/Enrique de la Osa

Enrique de la Osa/Reuters

Lightning flashes during a thunderstorm over Havana, Cuba

epa05382771 Protesters take to the streets in support to the extension of acting President Jovelerme Privert's term, in Port-au-Prince, Haiti, 21 June 2016. The Haitian Parliament has not reached an agreement on the extension of acting President of Haiti Jocelerme Privert's term, which started in February pending a general election in no more than 120 days, nor the appointing of another interim leader, as hundreds of people took the streets supporting Privert.  EPA/BAHARE KHODABANDE

Bahare Khodabande/EPA

Protesters take to the streets in support to the extension of acting President Jovelerme Privert’s term, in Port-au-Prince, Haiti 

British prime minister, David Cameron, talks to the FT from downing street ahead of the EU referendum on Thursday.

Charlie Bibby/FT

David Cameron, British prime minister, photographed during an interview with Lionel Barber, FT editor, and George Parker, FT political editor, at Downing Street on Tuesday ahead of the EU referendum

epa05381363 A Fairfax County police officer outside the headquarters of the National Rifle Association (NRA) beneath a paper heart inscribed with the name of a victim of the Orlando shooting massacre in Fairfax, VA, USA, 21 June 2016. On 20 June, the US Senate failed to pass four gun control amendments in the wake of the largest mass shooting in US history.  EPA/JIM LO SCALZO

Jim Lo Scalzo/EPA

A paper heart inscribed with the name of a victim of the Orlando shooting massacre in Fairfax obscures the face of a Fairfax County police officer outside the headquarters of the National Rifle Association (NRA)

Motorists are pictured behind a glass during rush hours along Ayala Avenue in Manila's financial district Makati, Metro Manila, Philippines June 21, 2016. REUTERS/Erik De Castro

Erik De Castro/Reuters

Motorists during rush hour along Ayala Avenue in Manila’s financial district Makati, Metro Manila, Philippines

Participants perform yoga during World Yoga Day in New Delhi, India, June 21, 2016. REUTERS/Adnan Abidi

Adnan Abidi/Reuters

Participants perform yoga during World Yoga Day in New Delhi, India 

epa05380528 A young aboriginal dancer plays in the sand during the Kenbi Native land claim ceremony, near Darwin, Northern Territory, Australia, 21 June 2016. Australian Prime Minister Malcolm Turnbull is in Darwin to attend the deed handover ceremony settling Australia's oldest Aboriginal land rights claim.  EPA/LUKAS COCH AUSTRALIA AND NEW ZEALAND OUT

Lukas Coch/EPA

A young aboriginal dancer plays in the sand during the Kenbi Native land claim ceremony, near Darwin, Northern Territory, Australia. Australian Prime Minister Malcolm Turnbull is in Darwin to attend the deed handover ceremony settling Australia’s oldest Aboriginal land rights claim 

An emu runs to escape an approaching wildfire as it burns near Potrero, California, U.S. June 20, 2016.        REUTERS/Mike Blake - RTX2H8ZI

Mike Blake/Reuters

An emu runs to escape an approaching wildfire as it burns near Potrero, California