Update pip from 18.0 to 18.1

pyup-bot · pyup-bot · commit 4eba2810f099 · 2018-10-05T09:53:31.000-07:00
diff --git a/requirements_dev.txt b/requirements_dev.txt
@@ -1,4 +1,4 @@
-pip==18.0
+pip==18.1
 bumpversion==0.5.3
 wheel==0.31.1
 watchdog==0.9.0
