chore: add GitHub URL to setup configuration for PyPi (#233)

Author: andriyor

setup.py

@@ -11,6 +11,9 @@
       author='Michele Lacchia',
       author_email='[email protected]',
       url='https://radon.readthedocs.org/',
+      project_urls={
+        'Source': 'https://github.com/rubik/radon',
+      },
       download_url='https://pypi.python.org/radon/',
       license='MIT',
       description='Code Metrics in Python',