Update PyPI URLs

Author: mstarzyk

setup.py

@@ -61,8 +61,8 @@ def run(self):
     description='Seamless operability between C++11 and Python',
     author='Wenzel Jakob',
     author_email='wenzel.jakob@epfl.ch',
-    url='https://github.com/pybind11/pybind11',
-    download_url='https://github.com/pybind11/pybind11/tarball/v' + __version__,
+    url='https://github.com/pybind/pybind11',
+    download_url='https://github.com/pybind/pybind11/tarball/v' + __version__,
     packages=['pybind11'],
     license='BSD',
     headers=headers,