Clarify if it should be `maybe-user-info-from-request` or `user-info-from-request`

[neshtea]

The readme tells the user to

Use active.clojure.openid/user-info-from-request to obtain information about the logged-in user in your handlers from the current request.

However, there is no such function besides a declare in openid.clj that is never implemented. There is, however, a maybe-user-info-from-request that seems to serve that purpose.

Two things

1. we need to be clear on which one it should be
2. advertise the right function-name and remove the unused one from the readme/declare-statement

[dfrese]

The 'declare' is already removed in #11

[neshtea]

The 'declare' is already removed in #11

I'm closing this then.