Added CRUD authentification to Bands
Added basic listing of Band's Artists
Added basic view of Artist's Bands
Created ArtistBandJoinRequest model for invitations to Bands + tests
Added feature for managing Artist's join requests from and to Bands
Sending invitations and requests to join the Band
Refactored Band controller, routes + moved invitation/request methods to Artist controller
Created get_full_name and get_legal_name methods in Artist model + tests
Added get_printable_name to Artist model + tests
Added managing members and requests in Bands + Refactored