Fix test failure in new test due to division changes in Python 3
Fix test failure in new test due to division changes in Python 3

In Python 3 (through PEP 238), division behavior changed such that it always
returns a float. This proceeds to cause problems with the CouchDB query
parser, so we change the test case to use the floor division operator
(which has the same behavior as default Python 2 division).

infinit/couchdb-python,djc/couchdb-python,djc/couchdb-python