Supply interval param for creating the subscription

{month, year} work; needs testing for others

stripe_utils.py

@@ -278,7 +278,8 @@ class StripeUtils(object):
         client.put("/v1/stripe_plans", json.dumps({"plans": list(stripe_plans)}))
 
     @handleStripeError
-    def get_or_create_stripe_plan(self, amount, name, stripe_plan_id):
+    def get_or_create_stripe_plan(self, amount, name, stripe_plan_id,
+                                  interval=INTERVAL):
         """
         This function checks if a StripePlan with the given
         stripe_plan_id already exists. If it exists then the function
@@ -290,6 +291,8 @@ class StripeUtils(object):
         :param stripe_plan_id: The id of the Stripe plan to be
                created. Use get_stripe_plan_id_string function to
                obtain the name of the plan to be created
+        :param interval: The interval for subscription {month, year}. Defaults
+               to month if not provided
         :return: The StripePlan object if it exists else creates a
                Plan object in Stripe and a local StripePlan and
                returns it. Returns None in case of Stripe error
@@ -309,7 +312,7 @@ class StripeUtils(object):
                     logger.debug("Plan {} does not exist in Stripe, Creating")
                     plan_obj = self.stripe.Plan.create(
                         amount=amount,
-                        interval=self.INTERVAL,
+                        interval=interval,
                         name=name,
                         currency=self.CURRENCY,
                         id=stripe_plan_id)

ucloud_pay.py

@@ -295,7 +295,7 @@ class ProductOrder(Resource):
                 plan_id = get_plan_id_from_product(product_obj)
                 res = stripe_utils.get_or_create_stripe_plan(
                     stripe_plan_id=plan_id, amount=product_obj["price"],
-                    name=plan_id
+                    name=plan_id, interval=product_obj["recurring_period"],
                 )
                 if res["response_object"]:
                     logging.debug("Obtained plan {}".format(plan_id))