Add locations and save them, remove locations and delete them

lib/screens/locations.dart

@@ -24,7 +24,11 @@ class _LocationsState extends State<Locations> {
     });
   }
 
-  void deleteLocation(String name) {}
+  void deleteLocation(String name) {
+    setState(() {
+      locations = UserPreferences.deleteLocation(name);
+    });
+  }
 
   @override
   Widget build(BuildContext context) {