feat(app-minimize): add AppMinimize plugin (#1501)

* typo(barcode-scanner): fixe circle lint error

* typo(docs):  Unified the documentations

In some plugins the typescript markup was missing.
I also unified the console.log string from console.log("hello") to console.log('Hello') so any plugin page look the same.

* Added AppMinimize plugin

* promisse

* usage

src/@ionic-native/plugins/app-minimize/index.ts

@@ -0,0 +1,42 @@
+import { Plugin, Cordova, IonicNativePlugin } from '@ionic-native/core';
+import { Injectable } from '@angular/core';
+
+/**
+ * @name App Minimize
+ * @description
+ * AppMinimize is a plugin to minimize the application on android devices
+ *
+ * @usage
+ * ```typescript
+ * import { AppMinimize } from '@ionic-native/app-minimize';
+ *
+ *
+ * constructor(private appMinimize: AppMinimize) { }
+ *
+ * ...
+ *
+ * this.plugin.minimize().then(
+ *   success => console.log('Closed'),
+ *   err => console.log('Something went wrong')
+ * );
+ *
+ * ```
+ */
+@Plugin({
+  pluginName: 'AppMinimize',
+  plugin: 'https://github.com/tomloprod/cordova-plugin-appminimize.git',
+  pluginRef: 'cordova.plugins.appMinimize',
+  repo: 'https://github.com/tomloprod/cordova-plugin-appminimize',
+  platforms: ['Android']
+})
+@Injectable()
+export class AppMinimize extends IonicNativePlugin {
+
+  /**
+   * Minimizes the application
+   * @return {Promise<any>}
+   */
+  @Cordova()
+  minimize(): Promise<any> { return; }
+
+}