Fix flaky test TestPullAllTagsFromCentralRegistry

This test was directly comparing lines of output from "docker images".
Sometimes, when busybox had been pushed to the hub recently, the
relative creation times would differ like this:

... obtained []string = []string{"busybox", "latest", "d9551b4026f0", "27", "minutes", "ago", "1.113", "MB"}
... expected []string = []string{"busybox", "latest", "d9551b4026f0", "26", "minutes", "ago", "1.113", "MB"}

Fixing by removing the time-since-creation fields from the comparison.

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>

integration-cli/docker_cli_pull_test.go

@@ -123,6 +123,19 @@ func (s *DockerHubPullSuite) TestPullAllTagsFromCentralRegistry(c *check.C) {
 	c.Assert(latestLine, checker.Not(checker.Equals), "", check.Commentf("no entry for busybox:latest found after pulling all tags"))
 	splitLatest := strings.Fields(latestLine)
 	splitCurrent := strings.Fields(splitOutImageCmd[1])
+
+	// Clear relative creation times, since these can easily change between
+	// two invocations of "docker images". Without this, the test can fail
+	// like this:
+	// ... obtained []string = []string{"busybox", "latest", "d9551b4026f0", "27", "minutes", "ago", "1.113", "MB"}
+	// ... expected []string = []string{"busybox", "latest", "d9551b4026f0", "26", "minutes", "ago", "1.113", "MB"}
+	splitLatest[3] = ""
+	splitLatest[4] = ""
+	splitLatest[5] = ""
+	splitCurrent[3] = ""
+	splitCurrent[4] = ""
+	splitCurrent[5] = ""
+
 	c.Assert(splitLatest, checker.DeepEquals, splitCurrent, check.Commentf("busybox:latest was changed after pulling all tags"))
 }