Merge branch 'release/r2' into develop
Merge branch 'hotfix/issue_1' into develop
Updated grade wrapper to 1.10 and buildtools to 19.0.1
Added getPurchases.
Merge branch 'master' into develop

* master:
  Updated copyright and license information.
Fixed typo
Added isSigningSupported
Replaced magic number with API_VERSION
Removed package from log texts
Added simple getPurchase example
getPurchases requires not run in main thread.
Shows toast message if there is error while purchasing.
Revision update
Merge branch 'release/r3'