quick fix #503 - pin version of vue-turbolinks to 2.1.x as 2.2 causes errors

Author: jonasjabari

package.json

@@ -8,7 +8,7 @@
     "link-module-alias": "^1.2.0",
     "v-runtime-template": "^1.5.2",
     "vue": "^2.5.17",
-    "vue-turbolinks": "^2.1.0",
+    "vue-turbolinks": "~2.1.0",
     "vuex": "^3.0.1",
     "yarn": "^1.22.0"
   },