restore whitespace in unit tests.
restore whitespace in unit tests.

I had removed whitespace from strings in a couple of the unit tests,
introducing a test regression. It turns out the difference was that
I had lxml installed in my virtualenv, which behaves differently
from html5lib; where html5lib preserves whitespace. since html5lib
is specified in the requirements.txt, the unit tests should follow
its behavior.

This should fix issue #27

kylewm/mf2py,kylewm/mf2py,tommorris/mf2py,tommorris/mf2py