chore(package): fix rxjs dependency to 6.3.3 due to typings errors

Author: Neonox31

package.json

@@ -27,7 +27,7 @@
     "geojson": "^0.5.0",
     "hammer-timejs": "^1.1.0",
     "hammerjs": "^2.0.8",
-    "rxjs": "^6.0.0",
+    "rxjs": "6.3.3",
     "zone.js": "^0.8.26"
   },
   "devDependencies": {