The "nospace" directive instructs the shell completion logic to avoid
adding a space after completing the word. However, this feature was
broken in an older Cobra, and users still saw a space character added.
In most case we want the space because we anticipate that the user might
want to add extra arguments to the command.
The `--json` flag accepts a list of GraphQL fields to query for and
output in JSON format. To get the list of available flags, run the
command with a blank value for `--json`. Additional `--jq` and
`--template` flags are available just like in `gh api`.
This removes sensitivity to the BROWSER environment variable in tests
and makes it easier to verify the URL that the browser was invoked with
without having to stub sub-processes.
