Added the underscore node_module.

node_modules/underscore/modules/propertyOf.js

@@ -0,0 +1,10 @@
+import noop from './noop.js';
+import get from './get.js';
+
+// Generates a function for a given object that returns a given property.
+export default function propertyOf(obj) {
+  if (obj == null) return noop;
+  return function(path) {
+    return get(obj, path);
+  };
+}