Update docker image

Related-Prod: PROD-36767
Change-Id: Ifcff6cd0aef732e3d13af72a5b5b612c2954358c
diff --git a/Dockerfile b/Dockerfile
index 20c8f13..6f44744 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,7 @@
 FROM python:3.9.1-alpine3.13
 
+LABEL build_date="2022-02-03"
+
 WORKDIR /app
 ENV CRYPTOGRAPHY_DONT_BUILD_RUST=1