Refine setup.py to remove obsolete namespace_packages parameter

Author: frankyang0635

setup.py

@@ -88,7 +88,6 @@ def read(*rnames):
     download_url='http://github.com/chrismattmann/tika-python',
     license='Apache License version 2 ("ALv2")',
     packages=find_packages(exclude=['ez_setup']),
-    namespace_packages=['tika'],
     include_package_data=True,
     zip_safe=True,
     test_suite='tika.tests',