Reduce the required gobject-introspection version to 0.6.1
Reduce the required gobject-introspection version to 0.6.1

Mash seems to work with version 0.6.1 and that is the version
currently available in Ubuntu so it's much more convenient to only
require that.

clutter-project/mash,clutter-project/mash,clutter-project/mash,eliasbakken/mash,eliasbakken/mash