Removed deprecated methods from lib/path.js

lib/path.js

@@ -56,9 +56,6 @@ exports.dirname = function (path) {
   }
 };
 
-exports.filename = function () {
-  throw new Error("path.filename is deprecated. Please use path.basename instead.");
-};
 exports.basename = function (path, ext) {
   var f = path.substr(path.lastIndexOf("/") + 1);
   if (ext && f.substr(-1 * ext.length) === ext) {