Fix tests

One can use transforms with Browserify, so I added babelify in order to
compile all node modules to ES5.

app/services/ipfs.js

@@ -17,13 +17,13 @@ export default Ember.Service.extend({
 
   storeFile(content) {
     let ipfs = this.get('ipfs');
-    return ipfs.add(new ipfs.Buffer(content)).then((res) => {
+    return ipfs.add(new ipfs.Buffer(content)).then(res => {
       return res[0].hash;
     });
   },
 
   getFile(hash) {
-    return this.get('ipfs').cat(hash, { buffer: true }).then(res) => {
+    return this.get('ipfs').cat(hash, { buffer: true }).then(res => {
       return res.toString();
     });
   }

config/environment.js

@@ -21,6 +21,15 @@ module.exports = function(environment) {
       // when it is created
     },
 
+    browserify: {
+      transform: [
+        ["babelify", {
+          presets: ["es2015"],
+          global: true
+        }]
+      ]
+    },
+
     web3ProviderUrl: "https://parity.kosmos.org:8545",
     ethereumChain: "testnet",
     ipfs: {

package.json

@@ -19,6 +19,8 @@
     "deploy": "npm run build-prod && npm run update-version-file && bash scripts/deploy.sh"
   },
   "devDependencies": {
+    "babel-preset-es2015": "^6.22.0",
+    "babelify": "^7.3.0",
     "broccoli-asset-rev": "^2.4.5",
     "ember-ajax": "^2.4.1",
     "ember-browserify": "^1.1.13",