Change travis badge to branch devel
Test with gradle wrapper
Refresh README
Run unit tests on travis
Bump gradle plugin
Update travis config for gradle plugin
Update travis build to use new android env
Fix gradle output
Remove lint abort on error
Update build configuration
Accept android sdk license
Default group (fix #27)

Prevent deadlines to be created without group.
Previous deadlines without group will be assigned to the default one.
New icons/logos
Fix drawer toggle (#34)
Configurable default group label (#32)
Update translations
merge devel
Bump version
Fix translations