Update pytest from 3.2.4 to 3.4.1

Author: pyup-bot

requirements-dev.txt

@@ -12,7 +12,7 @@ ipdb==0.10.3
 motor==1.1
 pytest-cov==2.5.1
 pytest-sugar==0.9.0
-pytest==3.2.4
+pytest==3.4.1
 python-dateutil==2.6.1
 sqlalchemy==1.1.15
 trafaret==0.10.4