Move config provider to _init to decouple from app

remove app references from validators

util/config/validators/validate_database.py

@@ -7,7 +7,7 @@ class DatabaseValidator(BaseValidator):
   name = "database"
 
   @classmethod
-  def validate(cls, config, user, user_password):
+  def validate(cls, config, user, user_password, app):
     """ Validates connecting to the database. """
     try:
       validate_database_url(config['DB_URI'], config.get('DB_CONNECTION_ARGS', {}))