Merge pull request #2 from nrcmedia/content-available-support

Added support for content-available flag
Release 1.0.3
Destroy the gateway connection on error, so reconnection works also when the connection is dropped instead of closed.
Merge pull request #3 from nrcmedia/master

Destroy the gateway connection on error, so reconnection works also when the connection is dropped instead of closed.
Release 1.0.4
Not adding an alert key to the aps if the alert is not set