v0.3.7

Added

• Added documentation for everything apart from the model. If anything is missing, please let me know and I'll add it in the future.

Changed

• Moved several endpoints (save/remove/check albums/episodes etc.) from needless builders.
• Re-exported the error::Result type alias.
• In the recently played tracks endpoint, you can now either set before or after, not both (as per the Spotify API documentation).
• Renamed several builder methods from various names (e.g. follow, unfollow, set) to, simply, send.

Removed

• Removed the fields option from the get-playlist builder, as it would be used to filter responses, in which case a Playlist couldn't be deserialized
  properly. Users can do filtering by accessing specific fields of the Playlist struct anyway.