Explicitly include LICENSE in MANIFEST.in
Explicitly include LICENSE in MANIFEST.in

Seems that the comment in commit 8014897016ed (“Clean up MANIFEST.in
and remove unnecessary entries (#160)”) about setuptools automatically
including the LICENSE file was inaccurate.

Fixes #176

daviddrysdale/python-phonenumbers,daviddrysdale/python-phonenumbers,daviddrysdale/python-phonenumbers