Move config provider to _init to decouple from app

remove app references from validators

util/config/validators/validate_keystone.py

@@ -5,7 +5,7 @@ class KeystoneValidator(BaseValidator):
   name = "keystone"
 
   @classmethod
-  def validate(cls, config, user, user_password):
+  def validate(cls, config, user, user_password, app):
     """ Validates the Keystone authentication system. """
     if config.get('AUTHENTICATION_TYPE', 'Database') != 'Keystone':
       return