* 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
* Fixes#272 by refactoring global log to conventional global as used by logzero
* Remove unnecessary logger from download_single, which was a test case
* Remove unnecessary logger from main(), which was a test case