Request.POST comparison fails due to lists #16

Reproduce:

1. Perform a POST with some list data:

{'foo': ['1', '2']}

1. Use assert_matches_request in your test
2. See that it fails on:

nose.proxy.AssertionError: '2' != "['1', '2']"
- 2
+ ['1', '2']

Why?

self.assert_data_equal(wsgi_request.POST, sample_request['body'])
The comparison fails due to the fact that request['foo'] is '2' (as opposed to request.getlist('foo') which is ['1', '2'])

Some cleverness in assert_matches_request may need to happen to create an accurate dict based on what the sample request indicates is in the payload.