Bump redis from 3.3.7 to 3.3.8 (#265)

dependabot-preview[bot] · web-flow · commit 2235de74c7ff · 2019-08-20T05:59:03.000Z
diff --git a/requirements.txt b/requirements.txt
@@ -2,6 +2,6 @@ cherry_picker==1.3.2
 aiohttp==3.5.4
 gidgethub==3.1.0
 cachetools==3.1.1
-redis==3.3.7
+redis==3.3.8
 celery==4.3.0
 sentry-sdk==0.11.1
