bump rabbitmq to 3.8

3.7 is unmaintained since end of 2020 (both upstream and docker image).

Author: thomas-riccardi

test/worker/dmake.yml

@@ -27,7 +27,7 @@ env:
         AMQP_URL: amqp://1.2.3.4/prod
 
 docker_links:
-  - image_name: rabbitmq:3.7
+  - image_name: rabbitmq:3.8
     link_name: test-rabbitmq
     probe_ports:
       - 5672/tcp

tutorial/worker/dmake.yml

@@ -15,7 +15,7 @@ docker:
       - deploy/dependencies.sh
 
 docker_links:
-  - image_name: rabbitmq:3.7
+  - image_name: rabbitmq:3.8
     link_name: rabbitmq
     probe_ports:
       - 5672/tcp