Testing multiple items per preference (and typo errors fixed)

[pwqw]

What do you think about it?

I cant run the test because I believe that the Account app_id and secret_key are not valid.

======================================================================
ERROR: test_existing_notification (tests.test_views.CreateNotificationTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/user/django-mercadopago/tests/test_views.py", line 17, in setUp
    self.preference.submit()
  File "/home/user/django-mercadopago/django_mercadopago/models.py", line 201, in submit
    pref_result = mercadopago_service.create_preference(request)
  File "/home/user/django-mercadopago/.tox/py36/lib/python3.6/site-packages/mercadopago/mercadopago.py", line 181, in create_preference
    access_token = self.get_access_token()
  File "/home/user/django-mercadopago/.tox/py36/lib/python3.6/site-packages/mercadopago/mercadopago.py", line 79, in get_access_token
    raise MPInvalidCredentials(str(access_data))
mercadopago.mercadopago.MPInvalidCredentials: {'status': 400, 'response': {'message': 'Invalid client_id', 'error': 'bad_request', 'status': 400, 'cause': {'code': 11, 'description': 'Invalid client_id', 'data': None}}}

[pwqw]

The file could be simply named test/urls.py instead of test/test_urls.py really?

[WhyNotHugo]

Yup, test/urls.py is better.

[pwqw]

I miss a little detail in urls.py

[tadeo]

Hi @WhyNotHugo! Is this PR still considered to be accepted? I'm about using this app in a site and I can contribute code to make this work. Gracias y saludos desde Uruguay!

[WhyNotHugo]

Wow, it’s been a year, my deepest apologies!

I’ve been working on porting most of this library into django-payments, which has a better design in general, plus, it integrates multiple other payment methods though.

I doubt I’ll work on new features here myself. However, I won’t reject an updated version of this PR if the comments here are addressed.