This change adds metrics for rate limits. Rate limits are now recorded
via a rate limit check loop (as before), but in addition, we are now
taking the rate limit info that gets returned in all github responses
and we're recording that as it happens as opposed to every 30 seconds.
The loop remains to update rate limits even for credentials that are
used rarely.
This change also adds a credentials details page in the webUI.
Signed-off-by: Gabriel Adrian Samfira <gsamfira@cloudbasesolutions.com>