PyPI Release Version 0.8.1

This release represents a minor increment to correct package setup and structure to enable proper publication for the seminal release of PrefPy on PyPI. This commit revision is released on PyPI at https://pypi.python.org/pypi/prefpy. The PrefPy package is now available publically for installation alongside Python 3.4+ with the following command:

pip3 install prefpy

Future development will finalize, consolidate, and generalize the GMM algorithm implementation for any number of alternatives and any moment conditions.