fix travis yaml and test challenges

.travis.yml

@@ -1,7 +1,7 @@
 language: node_js
 
-services:
-  - mongodb
-
 node_js:
-  - '0.10'
+  - 'node'
+  - '1.6.4'
+
+sudo: false

package.json

@@ -11,7 +11,7 @@
     "prestart-production": "bower cache clean && bower install && gulp build",
     "start-production": "node pm2Start",
     "lint": "eslint --ext=.js,.jsx .",
-    "test": "mocha --compilers js:babel/register"
+    "test": "gulp test-challenges"
   },
   "license": "(BSD-3-Clause AND CC-BY-SA-4.0)",
   "dependencies": {