Fix syntax error (#121)

Author: hugovk

setup.py

@@ -65,7 +65,7 @@
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8'
     ],
-    project_urls: {
+    project_urls={
         'Documentation': 'https://certifiio.readthedocs.io/en/latest/',
         'Source': 'https://github.com/certifi/python-certifi',
     },