For reading the profiles metadata, we're using the train mock backend
through Inspec::Runner. The new `supports` feature never agrees with the
mock backend.
Now, it we figure out if this is a mock class and then just say that it
supports whatever we're asking for.
Tl;dr: there's probably a more beautiful solution to this.
Added a test case, but it fails -- while the command line interface
works fine.
