Add rmqtt-bench:latest

Author: rmqtt

Makefile

@@ -11,6 +11,8 @@ release:
 docker:
         docker build --no-cache -t rmqtt/rmqtt-bench:$$(git describe --tags $$(git rev-list --tags --max-count=1)) ./
         docker push rmqtt/rmqtt-bench:$$(git describe --tags $$(git rev-list --tags --max-count=1))
+        docker build --no-cache -t rmqtt/rmqtt-bench:latest ./
+        docker push rmqtt/rmqtt-bench:latest
 
 clean:
         cargo clean