Merge pull request #47 from buxx/pyup-scheduled-update-2018-08-20

requirements.txt

 future==0.16.0
 numpy==1.15.0
 pluggy==0.7.1
-psutil==5.4.6
+psutil==5.4.7
 py==1.5.4
 pyglet==1.3.2
-pytest==3.7.1
+pytest==3.7.2
 python-dateutil==2.7.3
 PyYAML==3.13
 redis==2.10.6