Handle api error json (#18)

* Handle api error json

* Fix get vehicles error handling
Update .env.template

src/components/VehicleAddForm/index.jsx

@@ -24,9 +24,9 @@ const MainForm = () => {
         vin: vinEl.current.value,
       };
 
-      await addVehicle(formData, authToken);
+      const result = await addVehicle(formData, authToken);
 
-      setMessage(`Added ${vinEl.current.value}`);
+      setMessage(`Added ${result.vin}`);
       vinEl.current.value = "";
     } catch (e) {
       setMessage(e.message);