Fix GitPython version to 0.3.2.RC1

Last version of GitPython lead to errors in the Zuul
merger and zuul in unable to clone a change.

On the 11/14/2014 GitPython project bump version to
0.3.2 and this version is broken for us.

Change-Id: Iaf5567a7f99cc5d0d688d3d36cab9d6a042187cf