filter: renamed FilterChain to FilterChainElement
notification: added ClientRepository
main: added simple dropwizard application which manages DataGrabberMain
db: added DI
notifications: added builder pattern to NotificationManager
notifications:  NotificationManager uses ClientRepository
notifications: removed db package
Moved integration tests to same package

Testing otherwise becomes so much more harder ...
integrationtests: added ClientRepositoryTest
notifications: moved entire rest api to rest package
notifications: renamed NotificationSender to Sender
notification: added di to NotificationManager
notification: injecting gcm api key into GcmSender