Failure stress test

Implemented an stress test in folder test.

Once the test starts, it will periodically send a notification to APNS. Once the user unplugs the ethernet cable or disconnects the WIFI, the errorCallback or the on "Error" method should be called.

Currently, I can't see a relation between the network state and the output of this script (i.e. when I unplug the ethernet cable, I don't see the errors, sometimes, when I plug back, the errors are displayed (many at a time)...)