Update unitests for make_offer/bid

Author: DavoudTaghawiNejad

unittest/buy.py

@@ -20,7 +20,7 @@ def one(self):
             self.money = self['money']
             self.price = random.uniform(0.0001, 1)
             quantity = random.uniform(0, self.money / self.price)
-            self.offer = self.buy(('buy', self.id + 1),
+            self.offer = self.make_bid(('buy', self.id + 1),
                                   'cookies', quantity, self.price)
             assert self.not_reserved('money') == self.money - \
                 quantity * self.price

unittest/sell.py

@@ -18,7 +18,7 @@ def one(self):
             self.cookies = self['cookies']
             self.price = random.uniform(0.0001, 1)
             quantity = random.uniform(0, self.cookies)
-            self.offer = self.sell(receiver=('sell', self.id + 1),
+            self.offer = self.make_offer(receiver=('sell', self.id + 1),
                                    good='cookies', quantity=quantity, price=self.price)
             assert self.not_reserved('cookies') == self.cookies - quantity