This commit hacks the existing repo clone tests into something usable by
the new isolated command. It went ok and was less effort than trying to
introduce the same kind of test format as repo view and gist create.
Also define a handful of utility methods:
- `New(owner, repo)`
- `FullName`: the name slash owner pair
- `FromFullName`: parse the name slash owner pair
- `FromURL`: parse a GitHub.com URL
- `IsSame(r1, r2)`: compare two repositories