Implementing django password validators for edX. This involves removing

the old validate password method and configuration values in favor of
AUTH_PASSWORD_VALIDATORS, a list of validators to use to check a
password. These include some that come straight from Django and some
that were written according to Django's specifications. This work also
included maintaining the current messaging as instruction text and
passing along restrictions for the password field.

lms/envs/devstack.py

@@ -142,9 +142,6 @@ FEATURES['ENABLE_MAX_FAILED_LOGIN_ATTEMPTS'] = False
 FEATURES['SQUELCH_PII_IN_LOGS'] = False
 FEATURES['PREVENT_CONCURRENT_LOGINS'] = False
 FEATURES['ADVANCED_SECURITY'] = False
-PASSWORD_MIN_LENGTH = None
-PASSWORD_COMPLEXITY = {}
-
 
 ########################### Milestones #################################
 FEATURES['MILESTONES_APP'] = True