Files were added to be built whether an extension is on or off.
New build tags were added for each extension, while minimal and extended disappeared.
added custom binary naming depending on extensions used and changed references from binary to binary-extended
added automated blackbox tests for sync, search, scrub, metrics
added contributor guidelines
Signed-off-by: Alex Stan <alexandrustan96@yahoo.ro>
Periodically poll registries and pull images according to sync's config
Added sync on demand, syncing when clients asks for an image which
zot doesn't have.
Signed-off-by: Petu Eusebiu <peusebiu@cisco.com>
