Merge pull request #6615 from ulyssessouza/bump-docker-py-3.7.2

Bump docker-py 3.7.2

requirements.txt

@@ -3,7 +3,7 @@ cached-property==1.3.0
 certifi==2017.4.17
 chardet==3.0.4
 colorama==0.4.0; sys_platform == 'win32'
-docker==3.7.1
+docker==3.7.2
 docker-pycreds==0.4.0
 dockerpty==0.4.1
 docopt==0.6.2