chore(tests): fix karma version to use unstable one

Author: pkozlowski-opensource

package.json

@@ -14,6 +14,7 @@
     "grunt-contrib-watch": "~0.3.1",
     "grunt-contrib-jshint": "~0.4.0",
     "grunt-html2js": "~0.1.3",
+    "karma": "~0.11.12 ",
     "grunt-karma": "~0.7.2",
     "node-markdown": "0.1.1",
     "semver": "~1.1.4",