Make Redis completely optional:

* Move Redis code into fakeldap, since it's the only thing that still uses it.
 * Adjust auth unittests to skip fakeldap tests if Redis isn't around.
 * Adjust auth unittests to actually run the fakeldap tests if Redis /is/ around.

nova/auth/manager.py

@@ -202,7 +202,7 @@ class AuthManager(object):
 
     def __new__(cls, *args, **kwargs):
         """Returns the AuthManager singleton"""
-        if not cls._instance:
+        if not cls._instance or ('new' in kwargs and kwargs['new']):
             cls._instance = super(AuthManager, cls).__new__(cls)
         return cls._instance