Add MusicLibrary, which encapsulates access to the albums
Add more test cases for MusicLibrary
Use the spec reporter because the default minitest is hard to read
Update Picker to use MusicLibrary

Trying to follow the SRP.
Use default reporter with color
Update Client to deal with the new pattern option
Fix bug in Client when instanciating the picker
Seems like the thor options don’t like #fetch
Add functionnal test for the new -p option