Scheduled weekly dependency update for week 22 (#296)

* Update sphinx from 1.7.4 to 1.7.5

* Update sqlalchemy from 1.2.7 to 1.2.8

Author: pyup.io bot

requirements-dev.txt

@@ -7,6 +7,6 @@ pytest-cov==2.5.1
 pytest-sugar==0.9.1
 PyMySQL>=0.7.5
 docker==3.3.0
-sphinx==1.7.4
+sphinx==1.7.5
 sphinxcontrib-asyncio==0.2.0
-sqlalchemy==1.2.7
+sqlalchemy==1.2.8