Update setuptools from 41.4.0 to 42.0.1 (#277)

requirements_dev.txt

@@ -1,6 +1,6 @@
 -r requirements.txt
 bumpversion==0.5.3
-setuptools==41.4.0
+setuptools==42.0.1
 wheel==0.33.6
 
 coverage>=4.5.2