Merge pull request #7139 from docker/dependabot/pip/certifi-2019.11.28

Bump certifi from 2017.4.17 to 2019.11.28

requirements.txt

@@ -1,7 +1,7 @@
 backports.shutil_get_terminal_size==1.0.0
 backports.ssl-match-hostname==3.5.0.1; python_version < '3'
 cached-property==1.3.0
-certifi==2017.4.17
+certifi==2019.11.28
 chardet==3.0.4
 colorama==0.4.3; sys_platform == 'win32'
 docker==4.1.0