Documentation for cookie value of geo_session

[krsyoung]

Just checking, the documentation indicates that the cookie should be called :geo_session, however in practice (and it code) it looks like it is called :geo_location, the same as the session key.

Just checking if this is intended or if the session key and cookie key were meant to be different? If they were meant to be the same I'll submit a PR to correct the doc.