Update gem specification.
Add faraday middleware. Refactor api communication classes.
Add login functionallity.
Interfaces code changes.
Add brckets for priority.
Change file structure.
Add method for playing tracking.
Change file structure. Add track's artist.
Move mix requests in separate file.
Code refactoring.
Code refactoring.
Merge branch 'master' of github.com:nataliq/mix_set