feat(video-player): Added video player plugin (#391)

* Added OneSignal wrapper

* documentation

* Changes for callback of notification revieced

* fixes for @Cordova decorators without Promise return

* Merge

* Improvements to OneSignal
extended init function with notificationOpenedCallback as an optional parameter

* Platforms removed
OneSignal supports more than only these 3 platforms. It's available to nearly all Cordova platforms.

* Init method turned into observable

* Screen Orientation Plugin added. Closes #342

* Added VideoPlayer plugin #318

src/index.ts

@@ -79,6 +79,7 @@ import {Toast} from './plugins/toast';
 import {TouchID} from './plugins/touchid';
 import {TwitterConnect} from './plugins/twitter-connect';
 import {Vibration} from './plugins/vibration';
+import {VideoPlayer} from './plugins/video-player';
 import {WebIntent} from './plugins/webintent';
 export * from './plugins/3dtouch';
 export * from './plugins/background-geolocation';
@@ -111,6 +112,7 @@ export * from './plugins/sms';
 export * from './plugins/spinnerdialog';
 export * from './plugins/toast';
 export * from './plugins/twitter-connect';
+export * from './plugins/video-player';
 export {
   ActionSheet,
   AdMob,
@@ -238,6 +240,7 @@ window['IonicNative'] = {
   TouchID: TouchID,
   Transfer: Transfer,
   TwitterConnect: TwitterConnect,
+  VideoPlayer: VideoPlayer,
   Vibration: Vibration,
   WebIntent: WebIntent
 };