Perform automatic role dependency resolution

You no longer need to supply role_dependencies in your test because the
script is capable of figuring them out on its own.
Add uniq to the dependency resolution resolver
Improve the dependency resolution detection

Remove all leading white space on the matches before awking it. This helps
remove roles that aren't really dependencies but were comments in your
documentation when using Ansigenome's meta files.

This may not be perfect but I think in the worst case scenario it may
download extra roles only when you specifically have this exact string
included somewhere in Ansigenome's meta fields:

- role: 'some role name that is not unique to a real dependency'

I do not think this happens once in the entire DebOps code base but it
could in theory happen.