Fix infinite loading bug

• Fixed a bug where selecting the grade 'Alle' would result in an infinite loading screen

Support older devices

• The app will now run on all Android devices >= SDK 16
• Information about the grade of the user is now being sent to firebase

Fix Icon(s) and false-positive push-notifications

• The notification Icons are now being properly displayed on newer OS's
• The push notification won't trigger anymore if the new plan isn't available
• The push notification now show's a variety of 'heute', 'morgen' combinations

Enforce course when fetching

This should prevent ghost push-notifications

Add two subject aliases

• 'powi' -> 'PoWi'
• 'sp' -> 'Sport'

Initial release!

v0.0.1

Add version