Add info about required, unautomated step to script

scripts/postgresql/switch_primary.sh

@@ -21,3 +21,4 @@ bundle exec knife ssh roles:postgresql_client -a knife_zero.host "sudo sed -r \"
 # TODO
 # 1. Change roles in node configs
 # 2. Converge new primary
+echo "You need to update the role in the '$new_primary_hostname' node config to 'postgres_primary' and converge it now."