juju quickstart -i hides some errors

[David Britton]

for instance:

dpb@helo:landscape-trunk$ juju quickstart -i https://foobar-bundle
ERROR subprocess encountered error code 2
dpb@helo:landscape-trunk$

When without the -i:

dpb@helo:landscape-trunk$ juju quickstart https://foobar-bundle
usage: juju-quickstart [-h] [-e ENV_NAME] [-n BUNDLE_NAME] [-i]
                       [--environments-file ENV_FILE]
                       [--gui-charm-url CHARM_URL] [--no-browser]
                       [--distro-only] [--ppa] [--version] [--debug]
                       [--description] [--upload-tools]
                       [--upload-series UPLOAD_SERIES]
                       [--constraints CONSTRAINTS]
                       [bundle]
juju-quickstart: error: unable to open bundle URL: [Errno -2] Name or service not known
ERROR subprocess encountered error code 2