Update UnifiedPush Client

This PR contains 2 JIRA items:


https://issues.jboss.org/browse/AGJS-206

* removing the double encode on the enpoint during an `unrgisterWithPushServer` call
* https://github.com/aerogear/aerogear-simplepush-server/pull/83 this pr will fix the issue with unregistering our SimplePush endpoints 

https://issues.jboss.org/browse/AGJS-207

* similar to this one: 10ff1a7aa69fa06dc739ec1bd1fd1f8ec7b0a7d0