move from docker.io

Followon to #7965 (mirror registry). mirror.gcr.io doesn't
cache all the images we need, and I can't find a way to
add to its cache, so let's just use quay.io for those
images that it can't serve.

Tools used:
  skopeo copy --all docker://docker.io/library/alpine:3.10.2 \
                    docker://quay.io/libpod/alpine:3.10.2

...and also:

    docker.io/library/alpine:3.2
    docker.io/library/busybox:latest
    docker.io/library/busybox:glibc
    docker.io/library/busybox:1.30.1
    docker.io/library/redis:alpine
    docker.io/libpod/alpine-with-bogus-seccomp:label
    docker.io/libpod/alpine-with-seccomp:label
    docker.io/libpod/alpine_healthcheck:latest
    docker.io/libpod/badhealthcheck:latest

Since most of those were new quay.io/libpod images, they required
going in through the quay.io GUI, image, settings, Make Public.

Signed-off-by: Ed Santiago <santiago@redhat.com>

pkg/bindings/test/images_test.go

@@ -166,7 +166,7 @@ var _ = Describe("Podman images", func() {
 
 		// Adding one more image. There Should be no errors in the response.
 		// And the count should be three now.
-		bt.Pull("busybox:glibc")
+		bt.Pull("testimage:20200929")
 		imageSummary, err = images.List(bt.conn, nil, nil)
 		Expect(err).To(BeNil())
 		Expect(len(imageSummary)).To(Equal(3))