Environmental variables should have the prefix SPOTIFY_

[marioortizmanero]

The environmental variable names currently are CLIENT_ID, CLIENT_SECRET and REFRESH_TOKEN. I think it would be a better idea to use these same names with the prefix SPOTIFY_ to avoid name collisions with other programs/libraries that use OAuth2, like SPOTIFY_CLIENT_ID.

By the way, I'll leave for 3-4 days so I won't be able to respond to issues/PRs.

[ramsayleung]

I think it would be a better idea to use these same names with the prefix SPOTIFY_ to avoid name collisions with other programs/libraries that use OAuth2, like SPOTIFY_CLIENT_ID.

I think it will be better to have the prefix RSPOTIFY_ just avoid name collisions with other Spotify libraries.

[marioortizmanero]

That's not a bad idea either. I think collisions with other Spotify libraries aren't that bad because you can share the credentials, but I'd rather keep it trouble-free with RSPOTIFY-