We used to do the equivalent of `rootCmd.SetOut(os.Stdout)` because we
thought that Cobra's "Out" stream represents standard output. However,
upon closer inspection it turns out that this is Cobra's stream for
usage errors and deprecation warnings, and those we want written to
stderr as well. It is not clear to me why Cobra maintains a distinction
between "Out" and "Err" streams since both seem to go to sdterr by
default.
This change also ceases our usage of `command.Print()` functions in
favor of explicitly writing to `IOStreams.Out/ErrOut`.
GitHub user/repo names are case insentitive. This can cause issues when dealing with
repos programmatically using systems that aren't aware of this (e.g. go packages).
This commit updates the cloning logic of the CLI to query the API for the canonical
capitalization and uses that for the clone operation.
Fixes: #1845
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.
