Add RabbitMQ version 4.2 to CI matrix

Author: inikulshin

.github/workflows/ci.yml

@@ -77,7 +77,7 @@ jobs:
     strategy:
       max-parallel: 6
       matrix:
-        rabbitmq: ['3.13', '4.0', '4.1']
+        rabbitmq: ['3.13', '4.0', '4.1', '4.2']
         # os: [ubuntu-latest, windows-latest]
         os: [ubuntu-latest]
         include: