## Changes
Git repos hosted over HTTP do not support shallow cloning. This PR adds
retry logic if we detect shallow cloning is not supported.
Note I saw the match string `dumb http transport does not support
shallow capabilities` being reported in for different hosts on the
internet, so this should work accross a large class of git servers.
Howerver, it's not strictly necessary to have the `--depth` flag so we
can remove it if this issue is reported again.
## Tests
Tested manually. `bundle init` successfully downloads the private HTTP
repo reported during by internal user.