Migrate/androidstudio

[imran0101]

Migrating to Android Studio.

• Added Gradle support.
• Resolve issues with Manifest merging.
• External libraries put in the /libraries folder
• Dependencies added to build.gradle file.
• GitIgnore updated to include Android Studio build files.
• Sample Api Keys file for adding user test keys.

  85

[vinaysshenoy]

Please update your branches and do the migration from android-studio-migration instead of android-studio-migration and give the pull request back to android-studio-migration.