Added android as a browser for testing fixed tests accordingly

This PR requires https://github.com/LearnBoost/engine.io-parser/pull/8 to be merged. It adds android to the browsers used for testing in saucelabs, and introduces a couple necessary fixes to the tests to make them pass on android too. 

It seems that WebSocket connections do not work on the android emulator. At least when I try making connections, and upgrade event is never fired. This is why ws tests are disabled for android browsers.