GitLab

* Update plugin to use CocoaPods <framework> references in plugin.xml.

Requires cordova-ios 4.3.0 or greater, and cordova-cli 6.4.0 or greater.

Add GoogleCloudMessaging CocoaPod v1.2.0
Add GGLInstanceID CocoaPod v1.2.1
Update package.json for cordovaDependencies cordova and cordova-ios
Update plugin.xml for cordova and cordova-ios dependencies in <engines>

* Update README and INSTALLATION docs for CocoaPods support.

* Updated plugin.xml version to 1.9.0