DOC: Updated kurt docstring (for pandas sprint)
Assigned docstring for pandas documentation sprint

Please note that I also removed **kwargs from the call signature here as they were not being used, so I thought it would be strange to document. For what it's worth I started a discussion on the G[oogle groups list ](https://groups.google.com/forum/#!topic/pandas-documentation-sprint/P5_av_VuV6E)to see if that's the best way to handle or if we wanted to go a different path