Integration test two apps

Use localhost for app_with_roles and 127.0.0.1 for app. Confirm we can
deploy both and the respond to requests. Ensure the proxy is removed
once both have been removed.

test/integration/docker/deployer/app_with_roles/config/deploy.yml

@@ -1,5 +1,5 @@
-service: app
-image: app
+service: app_with_roles
+image: app_with_roles
 servers:
   web:
     hosts:
@@ -14,6 +14,7 @@ drain_timeout: 2
 readiness_delay: 0
 
 proxy:
+  host: localhost
   healthcheck:
     interval: 1
     timeout: 1