Basic gradle build
Added all gradle wrapper files.
Added basic gradle support for the test project.
Working ProvigenTests gradle configuration.
Removed useless files.
New travis build based on gradle.
Removed unneeded wait_for_emulator file.
Run only the tests of the ProviGenTests project.
Wait for the emulator using the travis provided script.
Update README.md
Merge branch 'gradle-support'
Upgraded to android gradle plugin version 0.12.2
Updated gradle version and android gradle plugin version.
Add android-21 to the travis build and upgrade build tools used by travis.
Added target android-21.
Merge pull request #1 from TimotheeJeannin/master

20141223