Fix missing import, include review id in JSON

canteeneo/api.py

 from canteeneo import app, db, auth
-from flask import jsonify, request, g
+from flask import jsonify, request, g, abort
 from flask.views import MethodView
 from models import Dish, Stall, Location, User, DishReview, StallReview, DishType, DishCuisine
 from datetime import datetime
@@ -248,6 +248,7 @@ def review_obj(review):
     if review is None:
         return None
     return {
+        'id': review.id,
         'title': review.title,
         'rating': review.rating,
         'user_id': review.user_id,