setup.py: Don't install the 'tests' package
setup.py: Don't install the 'tests' package

This package is useful for testing, but not namespaced appropriately
for a system-wide install ;).  For docs on the exclude syntax, using
this exact situation as an example, see [1].

[1]: https://pythonhosted.org/setuptools/setuptools.html#using-find-packages

heynemann/pyvows,marcelometal/pyvows