Scheduled weekly dependency update for week 11 (#271)

* Update flake8 from 3.4.1 to 3.5.0

* Update ipython from 6.1.0 to 6.2.1

* Update pytest from 3.4.0 to 3.4.2

* Update sphinx from 1.6.5 to 1.7.1

* Update sqlalchemy from 1.2.4 to 1.2.5

Author: pyup.io bot

requirements-dev.txt

@@ -1,10 +1,10 @@
 coverage==4.5.1
-flake8==3.4.1
+flake8==3.5.0
 ipdb==0.11
-ipython==6.1.0
-pytest==3.4.0
+ipython==6.2.1
+pytest==3.4.2
 pytest-cov==2.5.1
 pytest-sugar==0.9.1
-sphinx==1.6.5
+sphinx==1.7.1
 sphinxcontrib-asyncio==0.2.0
-sqlalchemy==1.2.4
+sqlalchemy==1.2.5