Fix: Work around PHP bug with Unix domain socket (UDS) paths for Mac OS X (#123 by @andig)

Fix: Fix SecureServer to return null URI if server socket is already closed (#129 by @clue)

Improve test suite by adding forward compatibility with PHPUnit v5 and forward compatibility with upcoming EventLoop releases in tests and test Mac OS X on Travis (#122 by @andig and #125, #127 and #130 by @clue)

Readme improvements (#118 by @jsor)