update plunkers versions

Author: Foxandxss

public/docs/_examples/systemjs.config.plunker.js

@@ -5,9 +5,9 @@
  */
 (function(global) {
 
-  var ngVer = '@2.0.0-rc.3'; // lock in the angular package version; do not let it float to current!
-  var routerVer = '@3.0.0-alpha.7'; // lock router version
-  var formsVer = '@0.1.1'; // lock forms version
+  var ngVer = '@2.0.0-rc.4'; // lock in the angular package version; do not let it float to current!
+  var routerVer = '@3.0.0-alpha.8'; // lock router version
+  var formsVer = '@0.2.0'; // lock forms version
   var routerDeprecatedVer = '@2.0.0-rc.2'; // temporarily until we update all the guides
 
   //map tells the System loader where to look for things