The request to authenticate.
Optionaloptions: anyOptions passed to the strategy.
Authenticate user, with optional info.
Strategies should call this function to successfully authenticate a
user. user should be an object supplied by the application after it
has been given an opportunity to verify credentials. info is an
optional argument containing additional user information. This is
useful for third-party authentication strategies to pass profile
details.
Optionalinfo: any
Performs authentication for the request. Note: Virtual function - re-implement in the strategy.