Merge pull request #7654 from docker/dependabot/pip/docker-4.3.0

Bump docker from 4.2.2 to 4.3.0

requirements.txt

@@ -4,7 +4,7 @@ certifi==2020.6.20
 chardet==3.0.4
 colorama==0.4.3; sys_platform == 'win32'
 distro==1.5.0
-docker==4.2.2
+docker==4.3.0
 docker-pycreds==0.4.0
 dockerpty==0.4.1
 docopt==0.6.2