Merge pull request #193 from akkie/master

Implement state provider for OAuth2 protocol
Fixed small but important typo in HeaderAuthenticatorSettings doc string
Merge pull request #195 from stephenmuss/master

Fixed small but important typo in HeaderAuthenticatorSettings doc string
Use "Read The Docs" for the documentation
Merge pull request #196 from akkie/doc

Use "Read The Docs" for the documentation