Fixing bug: AttributeError: type object 'Float' has no attribute 'from_s...

...tream' of python-tds

I installed [django-sqlserver](https://bitbucket.org/cramm/django-sqlserver/overview) and pytds to work with a database in SQL Server 2005. When I ran the command `inspectdb` I got this:

      File "/home/diegueus9/dev/whatsup/local/lib/python2.7/site-packages/pytds/tds.py", line 3411, in find_result_or_done
        self.process_token(marker)
      File "/home/diegueus9/dev/whatsup/local/lib/python2.7/site-packages/pytds/tds.py", line 3345, in process_token
        return handler(self)
      File "/home/diegueus9/dev/whatsup/local/lib/python2.7/site-packages/pytds/tds.py", line 3458, in <lambda>
        TDS7_RESULT_TOKEN: lambda self: self.tds7_process_result(),
      File "/home/diegueus9/dev/whatsup/local/lib/python2.7/site-packages/pytds/tds.py", line 2440, in tds7_process_result
        self.get_type_info(curcol)
      File "/home/diegueus9/dev/whatsup/local/lib/python2.7/site-packages/pytds/tds.py", line 2407, in get_type_info
        curcol.type = self.get_type_factory(type_id).from_stream(r)
    AttributeError: type object 'Float' has no attribute 'from_stream'