Added the underscore node_module.

node_modules/underscore/modules/pairs.js

@@ -0,0 +1,13 @@
+import keys from './keys.js';
+
+// Convert an object into a list of `[key, value]` pairs.
+// The opposite of `_.object` with one argument.
+export default function pairs(obj) {
+  var _keys = keys(obj);
+  var length = _keys.length;
+  var pairs = Array(length);
+  for (var i = 0; i < length; i++) {
+    pairs[i] = [_keys[i], obj[_keys[i]]];
+  }
+  return pairs;
+}