Conformance walker should handle nested/adjacent Describes

This also revealed that the regex for Context was too generous and would
catch things like SecurityContext or ContextWithFoo(...) calls

This ensures that test suites with a ineligible tag in their top-level
Describe will be rejected from promotion to conformance

test/conformance/walk_test.go

@@ -69,6 +69,23 @@ var _ = framework.KubeDescribe("Feature", func() {
 		Description: `By default the stdout and stderr from the process
 being executed in a pod MUST be sent to the pod's logs.` + "\n\n"}},
 	},
+	// SIGDescribe + KubeDescribe + It, Describe + KubeDescribe + It
+	{"e2e/foo.go", `
+var _ = framework.SIGDescribe("Feature", func() {
+	KubeDescribe("Described by", func() {
+		// Description: description1
+		framework.ConformanceIt("A ConformanceIt", func() {})
+	})
+	Describe("Also described via", func() {
+		KubeDescribe("A nested", func() {
+			// Description: description2
+			framework.ConformanceIt("ConformanceIt", func() {})
+		})
+	})
+})`, []conformanceData{
+		{URL: "https://github.com/kubernetes/kubernetes/tree/master/e2e/foo.go#L6", TestName: "Feature Described by A ConformanceIt", Description: "description1\n\n"},
+		{URL: "https://github.com/kubernetes/kubernetes/tree/master/e2e/foo.go#L11", TestName: "Feature Also described via A nested ConformanceIt", Description: "description2\n\n"},
+	}},
 	// KubeDescribe + Context + It
 	{"e2e/foo.go", `
 var _ = framework.KubeDescribe("Feature", func() {
@@ -101,7 +118,7 @@ func TestConformance(t *testing.T) {
 		*confDoc = true
 		tests := scanfile(test.filename, code)
 		if !reflect.DeepEqual(tests, test.output) {
-			t.Errorf("code:\n%s\ngot  %v\nwant %v",
+			t.Errorf("code:\n%s\ngot  %+v\nwant %+v",
 				code, tests, test.output)
 		}
 	}