Change order of CLI test assertions

So that you get useful error messages from STDERR before comparing
whether the exit code is correct or not.

cmd/root_test.go

@@ -15,9 +15,9 @@ var _ = Describe("Root", func() {
 			command := exec.Command(pathCLI, "--help")
 			session, err := gexec.Start(command, GinkgoWriter, GinkgoWriter)
 			Expect(err).ShouldNot(HaveOccurred())
-			Eventually(session).Should(gexec.Exit(0))
-			Eventually(session.Out).Should(gbytes.Say("Usage:"))
 			Eventually(session.Err.Contents()).Should(BeEmpty())
+			Eventually(session.Out).Should(gbytes.Say("Usage:"))
+			Eventually(session).Should(gexec.Exit(0))
 		})
 	})
 })