Update repo link for PyPI page

Author: oscarbenjamin

setup.py

@@ -87,7 +87,7 @@
     long_description=open('README.md').read(),
     long_description_content_type='text/markdown',
     version='0.4.2',
-    url='https://github.com/python-flint/python-flint',
+    url='https://github.com/flintlib/python-flint',
     author='Fredrik Johansson',
     author_email='[email protected]',
     license='MIT',