Add Push Notification Sending with Houston. Add cleanup of unregistered devices.
Fix an error with Houston::Client
Commit the fix in the pre-commit hook
Merge pull request #47 from elisapp/push_notification_scheduling

Add Push Notification Sending
Merge pull request #48 from elisapp/user_interface

User interface
Fix various things. Add sample set for Handball.
Merge branch 'master' of https://github.com/elisapp/elis
Fix style violations
Merge remote-tracking branch 'origin/master' into user_interface