This subcommand is so that users can get a nice commented version of the
ocid configuration file. This comes from the "current" version of the
configuration (allowing somone to get their custom configuration as a
file). It also has a --default option.
In addition, update the tests to use `ocid config` so that we test this
setup (the loading and saving of the options).
Signed-off-by: Aleksa Sarai <asarai@suse.de>
