Recursively build and diff Kustomizations

Signed-off-by: Boris Kreitchman <bkreitch@gmail.com>

cmd/flux/diff_kustomization_test.go

@@ -97,6 +97,12 @@ func TestDiffKustomization(t *testing.T) {
 			objectFile: "",
 			assert:     assertGoldenFile("./testdata/diff-kustomization/nothing-is-deployed.golden"),
 		},
+		{
+			name:       "diff with recursive",
+			args:       "diff kustomization podinfo --path ./testdata/build-kustomization/podinfo-with-my-app --progress-bar=false --recursive --local-sources GitRepository/default/podinfo=./testdata/build-kustomization",
+			objectFile: "./testdata/diff-kustomization/my-app.yaml",
+			assert:     assertGoldenFile("./testdata/diff-kustomization/diff-with-recursive.golden"),
+		},
 	}
 
 	tmpl := map[string]string{