There is no guarntee that pillars are loaded before pillars-from-file
as result we cant assume variables defined via pillars: are available
when pillars-from-file is loaded. Move 'source' definitions of repos to
.kitchen.yml as it uses ENV variable

Change-Id: Id94edd2351f17f5ac130db41a97d3be9cd5f3be4

Change-Id: Ib5db9f151baaf3fa0bca97a5457cf836bc57b88c