Google + Auth = Goth

Interface for retrieving access tokens, from either the Goth.TokenStore or the Google token API. The first request for a token will hit the API, but subsequent requests will retrieve the token from Goth’s token store

The Goth.TokenStore is a simple GenServer that manages storage and retrieval of tokens Goth.Token. When adding to the token store, it also queues tokens for a refresh before they expire: ten seconds before the token is set to expire, the TokenStore will call the API to get a new token and replace the expired token in the store