removed Abstract Base Class (ABC) module reference.  Implemented virtual behaviour for certain TableLoader functions via custom decorator.
removed Abstract Base Class (ABC) module reference.  Implemented virtual behaviour for certain TableLoader functions via custom decorator.

TableLoader inherits from Connector.

wikimedia/user_metrics,wikimedia/user_metrics,rfaulkner/wikipedia_user_metrics,rfaulkner/wikipedia_user_metrics,wikimedia/analytics-user-metrics,wikimedia/analytics-user-metrics,rfaulkner/wikipedia_user_metrics,wikimedia/user_metrics,wikimedia/analytics-user-metrics