According to rfc2616[1], the response from a server to a request with
bad credentials should be a 401 instead of a 403. Grin does not have
the concept of identities so it does not actually recognize a user
request with bad credentials.
[1] https://tools.ietf.org/html/rfc2616#section-10.4.2
* Add api_secret
* Add to base64 method
* Add basic auth in API
* Add Basic Auth to owner API
* Add flag to enable disable basic auth
* Add .api_secret file