Update pip from 9.0.1 to 18.0

pyup-bot · pyup-bot · commit 4a30b9e7538c · 2018-08-31T20:48:41.000-07:00
diff --git a/requirements_dev.txt b/requirements_dev.txt
@@ -1,4 +1,4 @@
-pip==9.0.1
+pip==18.0
 bumpversion==0.5.3
 wheel==0.30.0
 watchdog==0.8.3
