Dependabot was apparently not picking these up (and
several haven't had a release for a long time anyway).
Also move from github.com/go-check/check to its newly
declared (and go.mod-enforced) name gopkg.in/check.v1.
Signed-off-by: Miloslav Trmač <mitr@redhat.com>
We are not testing registry start-up performance, and killing the test
suite just because Travis is a bit busy doesn’t help; we’re much better
off with a test run which gives the registry a bit more time.