Add a dependency on play-services-auth.
Add a dependency on play-services-auth.

This is required to fix a compile error with Play Services v9.0+.
See the release notes for more information:
https://developers.google.com/android/guides/releases#may_2016_-_v90

MobileChromeApps/cordova-plugin-chrome-apps-identity,MobileChromeApps/cordova-plugin-chrome-apps-identity