[travis.yml] Fix destination to use iPhone 5S (fo be compatible with both iOS7 and iOS8 runtimes)
[travis.yml] Fix destination to use iPhone 5S (fo be compatible with both iOS7 and iOS8 runtimes)

HyprMXMobile/OHHTTPStubs,danielctull-forks/OHHTTPStubs,HyprMXMobile/OHHTTPStubs,tarbrain/OHHTTPStubs,danielctull-forks/OHHTTPStubs,danielctull-forks/OHHTTPStubs,HyprMXMobile/OHHTTPStubs,tarbrain/OHHTTPStubs,tarbrain/OHHTTPStubs,HyprMXMobile/OHHTTPStubs,danielctull-forks/OHHTTPStubs,tarbrain/OHHTTPStubs