Resolve "Resolve peer dependency warnings"

Closes #150 (closed)

frontend/src/components/AutoLogout.vue

@@ -72,7 +72,7 @@ export default class AutoLogout extends Vue {
 
   mounted () {
     // show notification on unload if logged in
-    window.onbeforeunload = event => {
+    window.onbeforeunload = (event: BeforeUnloadEvent) => {
       if (Authentication.isLoggedIn) {
         // return something to trigger the confirmation dialog
         // since firefox 44 it is no longer possible to show a custom confirmation message