Add retry failed CI jobs twice (#429)

.gitlab-ci.yml

@@ -47,6 +47,12 @@ default:
       else
         export DOCKER_IMAGE_TAG="${CI_COMMIT_SHORT_SHA}-beta"
       fi
+  retry:
+    max: 2
+    when:
+      - runner_system_failure
+      - unknown_failure
+      - api_failure
 
 stages:
   - build