Add fake Keystone

* enabled 'fake' authentication in nailgun by default
* add fake keystone API and middleware to nailgun
* fixed problem with not configured logging in
  keystoneclient - now fuelclient silents all logs
* removed TEST_MODE as it's not needed in fake auth

Related to blueprint access-control-master-node
Closes-Bug: 1340141
Change-Id: I76cb7d1cb19be8e0d23ecc03fdbc968b1eeaff5c
Merge "Add fake Keystone"