Update setuptools from 39.2.0 to 40.6.3 (#206)

requirements_dev.txt

@@ -1,7 +1,7 @@
 -r requirements.txt
 bumpversion==0.5.3
+setuptools==40.6.3
 wheel==0.32.3
-setuptools==39.2.0
 
 coverage>=4.5.2
 mock>=2.0.0