Raise minimum compatible Tabris.js version to 3.0

Tabris.js 3.0 is based on cordova-android 7.x which has a different
folder structure. In order to make the example functional under 3.0 we
have to adjust the example paths in the config.xml. The plugin itself
would not require an update.

Author: mpost

README.md

@@ -54,7 +54,7 @@ Feature | Supported platforms
 
 ## Compatibility
 
-Compatible with [Tabris.js](https://www.npmjs.com/package/tabris) ^2.2.0.
+Compatible with [Tabris.js](https://www.npmjs.com/package/tabris) 3.x.
 
 ## Plugin development