Tests - Fix mountAndGetRootNode usage + Add depth=1 test case

test/sample-components/depth-1-simple.tsx

@@ -0,0 +1,10 @@
+// import * as PropTypes from "prop-types";
+import * as React from "react";
+
+class CDepth1 extends React.Component {
+  render() {
+    return null;
+  }
+}
+
+export default CDepth1;

test/sample-components/depth-2-simple.tsx

@@ -7,8 +7,4 @@ class CDepth2 extends React.Component {
   }
 }
 
-// C.propTypes = {
-//   text: PropTypes.string.isRequired
-// };
-
 export default CDepth2;