Issues working with pygtk

[Gareth France]

I have been struggling to get my latest creation to package, whatever I 
try it fails trying to include pygtk. My builds are automated on git 
through travis and this seemed to be where the problem lay. Today though 
I thought I'd try a local build and it still fails.

The problem seems to be with the way it is obtaining pygtk as one of the 
python packages. It spits out this error at the end of the build:


********************************************************************
     * Building PyGTK using distutils is only supported on windows. *
     * To build PyGTK in a supported way, read the INSTALL file. *
********************************************************************


I presume that I need to add some entries to the yaml to instruct it to 
download and build pygtk rather than just including it as a python 
module. Being new to this I'm not sure where to start though.

Any help greatly appreciated.