If a repo did not exist, running matchers against it (such as `exist`)
were failing due to a bug in `#to_s` when fetching the repo name. The
`info` method would return nil and we'd still try to treat it as a hash.
This change ensures that info is always a hash, possibly empty if the
repo doesn't exist, and uses the repo name provided by the user rather
than shortening it to be consistent with our other resources which don't
manipulate the user input in the formatter.
Also added a method_missing to allow users to interrogate repo options,
such as baseurl or gpgcheck.
Signed-off-by: Adam Leff <adam@leff.co>
