Since the test suite is inlined, it makes sense to also have the test data installed alongside the test modules.
So all the content of the two top-level folders Data and TestData is now placed inside Lib/ufoLib/test/testadata.
The MANIFEST.in has been adjusted accordingly.
The `install_package_data` in setup.py ensures the package data specified in the manifest is installed with the package.
This way anyone who installs ufoLib (even the wheel from PyPI) can run the test suite with `pytest --pyargs ufoLib`.
