flutter_unity_widget 0.1.3+4

Flutter unity 3D widget for embedding unity in flutter

0.1.3+4

• Change input source of Flutter touch events so they work in Unity
• Instructions on how to implement Vuforia AR
• Fix postMessage throwing exceptions on Android
• Add video tutorial, replace unity-player with unity-classes in example
• Remove java and UnityPlayer changes to the windowmanager so it can be…