Use Chrome only for UI tests

Change-Id: Ica3dccf138bd1237cc808cd0c8df25372e4188d4

package.json

@@ -13,7 +13,6 @@
     "karma": "^0.12.23",
     "karma-chrome-launcher": "^0.1.5",
     "karma-cli": "0.0.4",
-    "karma-firefox-launcher": "^0.1.3",
     "karma-jasmine": "^0.2.2",
     "protractor": "~1.0.0"
   },

refstack-ui/tests/karma.conf.js

@@ -29,11 +29,10 @@ module.exports = function (config) {
 
         frameworks: ['jasmine'],
 
-        browsers: ['Firefox', 'Chrome'],
+        browsers: ['Chrome'],
 
         plugins: [
             'karma-chrome-launcher',
-            'karma-firefox-launcher',
             'karma-jasmine'
         ],