Really? Wow.

This is a fix for the sole failing test in the CI for these changes (in
tests/functional/test_debug.py::test_debug__library_versions). The
failure took me a fair bit of time to diagnose, but it looks like the
issue is that we're strictly comparing versions as strings. This is a
bad idea when they're not normalized.

src/pip/_vendor/vendor.txt

@@ -12,7 +12,7 @@ pep517==0.8.2
 progress==1.5
 pyparsing==2.4.7
 requests==2.24.0
-    certifi==2020.6.20
+    certifi==2020.06.20
     chardet==3.0.4
     idna==2.10
     urllib3==1.25.9