Update docs to include info that localflavor.br.forms.BRPhoneNumberField has support to 9 numbers fixes #24

The code is correct, but docstring need to be updated.
fix pep8, localflavor/br/forms.py:41:83: W291 trailing whitespace
Merge pull request #25 from fgmacedo/patch-1

Update docs: br.forms.BRPhoneNumberField has support to 9 numbers fixes #24