feat(push): add Browser Push notification support (#1848)

* Browser Push interface with options to use push notification with browsers , as a proxy to phonegap-plush-plugin

* making both properties optional

src/@ionic-native/plugins/push/index.ts

@@ -188,10 +188,25 @@ export interface AndroidPushOptions {
  topics?: string[];
 }
 
+export interface BrowserPushOptions {
+ /**
+ * Optional. Your GCM API key if you are using VAPID keys.
+ */
+ applicationServerKey?: string;
+
+ /**
+ * URL for the push server you want to use.
+ * Default: http://push.api.phonegap.com/v1/push Optional. 
+ */
+ pushServiceURL?: string;
+
+}
+
 export interface PushOptions {
  ios?: IOSPushOptions;
  android?: AndroidPushOptions;
  windows?: any;
+ browser?: BrowserPushOptions;
 }
 
 export type PushEvent = 'registration' | 'error' | 'notification';
@@ -237,7 +252,10 @@ export type PushEvent = 'registration' | 'error' | 'notification';
  * badge: true,
  * sound: 'false'
  * },
- * windows: {}
+ * windows: {},
+ * browser: {
+ * pushServiceURL: 'http://push.api.phonegap.com/v1/push'
+ * }
  * };
  *
  * const pushObject: PushObject = this.push.init(options);
@@ -257,6 +275,7 @@ export type PushEvent = 'registration' | 'error' | 'notification';
  * NotificationEventAdditionalData
  * IOSPushOptions
  * AndroidPushOptions
+ * BrowserPushOptions
  * PushOptions
  */
 @Plugin({