build: update karma runner dependencies

A new stable version of karma runner was released 2 days ago and
we need to bump up its version to restore compatibility with all
the karma plugins, otheriwse fresh npm install is failing.

package.json

@@ -25,10 +25,10 @@
     "grunt-contrib-uglify": "~0.2.7",
     "grunt-peg": "~1.0.0",
     "atpackager": "~0.2.2",
-    "karma": "~0.11.12",
-    "grunt-karma": "~0.7.2",
+    "karma": "~0.12.0",
+    "grunt-karma": "~0.8.0",
     "karma-commonjs": "0.0.6",
-    "karma-sauce-launcher": "~0.1.7",
+    "karma-sauce-launcher": "~0.2.2",
     "karma-mocha": "~0.1.1",
     "karma-expect": "~1.0.0",
     "karma-chrome-launcher": "~0.1.2",