Bump to v4.0.0.

nthArg.js

@@ -0,0 +1,25 @@
+import toInteger from './toInteger';
+
+/**
+ * Creates a function that returns its nth argument.
+ *
+ * @static
+ * @memberOf _
+ * @category Util
+ * @param {number} [n=0] The index of the argument to return.
+ * @returns {Function} Returns the new function.
+ * @example
+ *
+ * var func = _.nthArg(1);
+ *
+ * func('a', 'b', 'c');
+ * // => 'b'
+ */
+function nthArg(n) {
+  n = toInteger(n);
+  return function() {
+    return arguments[n];
+  };
+}
+
+export default nthArg;