To allow for diagnosing problems with SAML auth connection to IdP

Records what auth attributes the user is trying to authenicate with,
eg institution, email address, username etc.

A config flag is also made to allow one to turn on/of the recording
The data is only stored in the database and is not exposed to the site
itself

behatnotneeded

Change-Id: I5766cf64be048fd1fe0771c9aed3e83e888ff650
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>