* added the ability to get all artist's songs as suggested by #366
* added log to featch_all_albums_from_artist function and removed the use of a uri
* updated the functionality to get all albums with the ability to get singles
* updated main function with new write_all_albums_from_artist function to get all albums from an artist
* fixed typos
* updated test case for getting all albums from artist
* fixed typos
* Monkeypatch fetch user and use pytest.tempdir
* Cover spotify_tools.grab_album()
* Cover avconv conversion
* Cover grab_single()
* Reduce code repetition
* Move grab_playlist() to spotify_tools.py
* Move Spotify specific functions to spotify_tools.py
* Refactoring
* Return track list from write_tracks()
* Fix tests
* Cover more cases in generate_youtube_url()
* Test for unavailable audio streams
* Test for filename without spaces
* handle.py 100% coverage
* Improve config tests
* Speed up tests
* Install avconv and libfdk-aac
* Some cleaning
* FFmpeg with libfdk-aac, libopus
* Some refactoring
* Convert tmpdir to string
* Cover YouTube title when downloading from list
* Explicitly cover some internals.py functions
