class inhertance does not work for fetch method because its hard coded to return a GravitySpyTable

Created by: scottcoughlin2014

In [3]: Events
Out[3]: gravityspy.table.events.Events

In [4]: virgo_images = Events.fetch('gravityspy', 'updated_similarity_index WHERE ifo = \'V1\'')

In [6]: type(virgo_images)
Out[6]: gwpy.table.gravityspy.GravitySpyTable