tech(nodejs upgrade): upgraded to nodejs 4.0 for grunt build

circle.yml

 machine:
+  node:
+    version: 4.0
   environment:
     GOPATH: "/home/ubuntu/.go_workspace"
     ORG_PATH: "github.com/grafana"

package.json

@@ -53,8 +53,8 @@
     "tslint": "^2.5.0-beta"
   },
   "engines": {
-    "node": "0.10.x",
-    "npm": "1.2.x"
+    "node": "0.4.x",
+    "npm": "2.14.x"
   },
   "scripts": {
     "test": "grunt test",

public/app/features/dashboard/timepicker/timepicker.ts

@@ -202,8 +202,6 @@ export function settingsDirective() {
     templateUrl: 'app/features/dashboard/timepicker/settings.html',
     controller: TimePickerCtrl,
     scope: true,
-    link: function() {
-    }
   };
 }