Produce colored spec output on Windows console.

Hi,

I've enjoyed using your spec plugin, but moving over to my other computer running Windows I missed the nice colored output. Using the [colorama](https://pypi.python.org/pypi/colorama) plugin you can get colored output for spec.py also on the Windows console, although it does of course add another dependency.

Hope this can be useful.

Cheers,
-Vegar Guldal