Merge pull request #46 from buxx/pyup-scheduled-update-2018-08-13

requirements.txt

 Dijkstar==2.4.0
 freezegun==0.3.10
 future==0.16.0
-numpy==1.14.5
-pluggy==0.6.0
+numpy==1.15.0
+pluggy==0.7.1
 psutil==5.4.6
 py==1.5.4
 pyglet==1.3.2
-pytest==3.6.3
+pytest==3.7.1
 python-dateutil==2.7.3
 PyYAML==3.13
 redis==2.10.6