try crodwin
Replace ACRA with Fabric's Crashlytics.
Fully specifiy Fabric Plugin version
Remove superflous Crashlytics deps/definitions
add toast if api keys are missing, fixes #157
Fix ProGuard errors caused by stripped down GMS lib
Remove false signing config for release builds
Merge pull request #158 from gdg-x/feature/acra_to_fabric

Replace ACRA with Fabric's Crashlytics.