importing hypertools updates matplotlib rcParams

[paxtonfitzpatrick]

because of this line in draw.py:

hypertools/hypertools/plot/draw.py

Line 10 in cca1753

matplotlib.rcParams['pdf.fonttype'] = 42

looks like this is the last little change that was missed when fixing #210/#243. Doesn't have a huge impact as it only makes a difference when saving figures to PDFs, and in most cases users would probably want this setting enabled anyway. But still, we shouldn't be silently changing config options from another library on import.