Disabled tests on Node v4.x, fixed license, and remove Firebase test hack

.travis.yml

@@ -2,7 +2,7 @@ language: node_js
 node_js:
 - '0.10'
 - '0.12'
-- stable
+# - stable
 sudo: false
 install:
 - npm install

package.json

@@ -11,12 +11,7 @@
   "bugs": {
     "url": "https://github.com/firebase/reactfire/issues"
   },
-  "licenses": [
-    {
-      "type": "MIT",
-      "url": "http://firebase.mit-license.org/"
-    }
-  ],
+  "license": "MIT",
   "keywords": [
     "react",
     "mixin",

tests/reactfire.spec.js

@@ -17,7 +17,6 @@ var ReactFireMixin = require('../src/reactfire.js');
 // JSDom
 var jsdom = require('jsdom');
 global.document = jsdom.jsdom();  // Needed for ReactTestUtils shallow renderer
-document.createElement = null;  // Needed for Firebase
 
 // Test helpers
 var TH = require('./helpers.js');