Force alabaster theme to show GitHub stars count
Force alabaster theme to show GitHub stars count

For some reason we are getting Watchers count with 'latest' docs whereas
we get Stars count with 'stable' docs. I'm adding a github_type setting
in an attempt to align the two versions.

nicolaiarocci/cerberus,nicolaiarocci/cerberus,funkyfuture/cerberus,pyeve/cerberus,dkellner/cerberus,pyeve/cerberus,funkyfuture/cerberus,dkellner/cerberus