Scheduled weekly dependency update for week 14 (#279)

* Update ipython from 6.2.1 to 6.3.1

* Update pytest from 3.4.2 to 3.5.0

* Update docker from 3.1.4 to 3.2.1

* Update sphinx from 1.7.1 to 1.7.2

* Update sqlalchemy from 1.2.5 to 1.2.6

Author: pyup.io bot

requirements-dev.txt

@@ -1,12 +1,12 @@
 coverage==4.5.1
 flake8==3.5.0
 ipdb==0.11
-ipython==6.2.1
-pytest==3.4.2
+ipython==6.3.1
+pytest==3.5.0
 pytest-cov==2.5.1
 pytest-sugar==0.9.1
 PyMySQL>=0.7.5
-docker==3.1.4
-sphinx==1.7.1
+docker==3.2.1
+sphinx==1.7.2
 sphinxcontrib-asyncio==0.2.0
-sqlalchemy==1.2.5
+sqlalchemy==1.2.6