Merge pull request #36 from buxx/pyup-scheduled-update-2018-05-14

requirements.txt

-attrs==17.4.0
+attrs==18.1.0
 cocos2d==0.6.5
 Dijkstar==2.4.0
 freezegun==0.3.10
 py==1.5.3
 pyglet==1.3.2
 pytest==3.5.1
-python-dateutil==2.7.2
+python-dateutil==2.7.3
 PyYAML==3.12
 redis==2.10.6
 six==1.11.0
 tmx==1.9.1
-pytest-mock==1.9.0
+pytest-mock==1.10.0
 Pillow==5.1.0