Add unit tests for database
Fix audio unit tests
Fix file class
Implement PlaySong, Queue and Find
Rename attribute
Add __repr__ and __str__ for DB model
Fix docstrings
Implement add_song_metadata
Implement method for metadata fetching from raw audio file
Implement metadata storing and modifying
Add tests for DatabaseInterface and DB
Fix DB and DatabaseInterface according to tests
Implement NowPlaying and Queue
Update documentation
Fix pyglet requirement
Merge branch 'stealthyloner-dev'

Conflicts:
	requirements.txt