Fixed invalid json being generated.
Fixed response data is nil after post request. (Thanks to @fabiormoura)
Added Error code 400 to README.
Logging json before sending.
Removed Gcm::Connection.open.
Better logging
Using Rails.logger for logging
Merge branch 'master' of https://github.com/danpe/gcm_on_rails

Conflicts:
	lib/gcm_on_rails/app/models/gcm/notification.rb
	lib/gcm_on_rails/libs/connection.rb