dist-spec community is now maintaining its own conformance suite hosted
at https://oci.bloodorange.io which over time will be more complete.
This makes zot's compliance cli superfluous. Hence, deprecating the cli.
However, we keep the unit tests itself though.
This adds a new --json flag to the compliance subcommand, which
will output the compliance test results as minified JSON to stdout.
Also a few other small additions:
- Exit 1 if compliance tests fail
- Use random port for test server using freeport library (added)
Signed-off-by: Josh Dolitsky <393494+jdolitsky@users.noreply.github.com>
