Update docker from 3.5.0 to 3.5.1

Author: pyup-bot

requirements-dev.txt

@@ -6,7 +6,7 @@ pytest==3.9.1
 pytest-cov==2.6.0
 pytest-sugar==0.9.1
 PyMySQL>=0.9,<=0.9.2
-docker==3.5.0
+docker==3.5.1
 sphinx==1.8.1
 sphinxcontrib-asyncio==0.2.0
 sqlalchemy==1.2.12