Scheduled weekly dependency update for week 23 (#293)

* Update pytest from 3.6.0 to 3.6.1

* Update aiohttp from 3.3.0 to 3.3.1

* Update yarl from 1.2.4 to 1.2.5

Author: pyup.io bot

requirements-dev.txt

@@ -7,13 +7,13 @@ aioredis==1.1.0
 cryptography==2.2.2
 docker==3.3.0
 pynacl==1.2.1
-pytest==3.6.0
+pytest==3.6.1
 pytest-aiohttp==0.3.0
 pytest-cov==2.5.1
 pytest-mock==1.10.0
 pytest-sugar==0.9.1
-aiohttp==3.3.0
+aiohttp==3.3.1
 multidict==4.3.0
 chardet==3.0.4
-yarl==1.2.4
+yarl==1.2.5
 aiomcache==0.6.0