This release contains some minor bug fix and improvements.
- bugfix Correctly change from sandbox to production environment in APNS. This fixed issue 33.
- bugfix If a connection pool connecting with APNS closed, then any Close() operation on connections from the pool will cause a panic. This is a bug in connpool, and fixed in issue 37.
- improvement APNS: add content-available support. Fixed issue 36.
- improvement Set Keepalive for all TCP connections. In this case, we can discover connection failure quickly. Fixed issue 38.
- improvement @ is a valid character in subscriber and service names. Fixed issue 39.