chore(package): update xstream to version 5.0.6 (#50)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -44,7 +44,7 @@
     "typings": "^0.8.1",
     "uglify-js": "^2.6.2",
     "validate-commit-message": "^3.0.1",
-    "xstream": "^5.0.5"
+    "xstream": "^5.0.6"
   },
   "config": {
     "ghooks": {