Update requests from 2.20.1 to 2.21.0
diff --git a/tools/wptrunner/requirements_sauce.txt b/tools/wptrunner/requirements_sauce.txt
index 666db37..e38f4de 100644
--- a/tools/wptrunner/requirements_sauce.txt
+++ b/tools/wptrunner/requirements_sauce.txt
@@ -1,3 +1,3 @@
 mozprocess == 0.26
 selenium==3.141.0
-requests==2.20.1
+requests==2.21.0