added symlink dependencies for node_modules in Robo

RoboFile.php

@@ -3,11 +3,21 @@ class RoboFile extends \Robo\Tasks {
   function install() {
     $this->_exec('./composer.phar install');
     $this->_exec('npm install');
+    $this->symlinkDependencies();
   }
 
   function update() {
     $this->_exec('./composer.phar update');
     $this->_exec('npm update');
+    $this->symlinkDependencies();
+  }
+
+  function symlinkDependencies() {
+    // handlebars
+    $this->_symlink(
+      __DIR__.'/node_modules/handlebars/dist/handlebars.min.js',
+      __DIR__.'/assets/js/handlebars/handlebars.min.js'
+    );
   }
 
   function testUnit() {