obmc-gerrit: Add typing in requirements.txt

Otherwise it's missing the dependency.

Signed-off-by: Lei YU <yulei.sh@bytedance.com>
Change-Id: Ifb80954ca26fc089814e7b13522362f0dc6ab150
diff --git a/amboar/obmc-scripts/maintainers/requirements.txt b/amboar/obmc-scripts/maintainers/requirements.txt
index 579ac31..35e9db3 100644
--- a/amboar/obmc-scripts/maintainers/requirements.txt
+++ b/amboar/obmc-scripts/maintainers/requirements.txt
@@ -1,2 +1,3 @@
 requests
 sh
+typing