Upgrade gradle and lib versions.
The app didn't built. I've upgraded to a new version of libraries and tools, it forced me to enable multiDex. Then I've encountered the 'duplicate entry for common.annotations.Beta' error. I've fixed it by modifying the build.gradle file.
@orian according to Travis your changes make build to fail. Could you review changes?
I believe it's not possible to merge at this point. The Travis available version of libraries is older than the updated one. Can we make the PR wait for some time? I think someone may want to use it.
Please squash commits and do a force push. I see that your changes in travis are OK so we need to launch new travis job to check the result.
I've squashed commits. Sorry it took so long.