v0.3.0 Permissive mode

Add permissive mode, which will allow all requests but log an error if a valid authentication token is not provided.

v0.3.0-beta2 Fix logging in permissive mode

Add trailing newline to warning messages in stderr

v0.3.0-beta1 Support permissive mode

Permissive mode (#3)

* Add permissive mode to test authentication without denying clients.
This obviously does not set internalForwardedHeaderName in cases where the request would have been normally rejected.

* Update description of new options in README.md