Updating rxjs to 5.6.0-forward-compat.3

The project gets an error with its current state of rxjs: "^5.5.6". Upgraded to rxjs: "^5.6.0-forward-compat.3", as this will resolve the error.

Author: estrellajm

ngxs/package.json

@@ -26,7 +26,7 @@
     "@ngxs/logger-plugin": "^3.0.0-dev.706a0b9",
     "@ngxs/store": "^3.0.0-dev.706a0b9",
     "core-js": "^2.4.1",
-    "rxjs": "^5.5.6",
+    "rxjs": "^5.6.0-forward-compat.3",
     "zone.js": "^0.8.19"
   },
   "devDependencies": {