Multiple labels

[gleopoldo]

What changed?

1. I've fixed the multi-label syntax in cypher queries. The old syntax was using a comma separator for multiple labels, but cypher docs uses double colon instead

2. The integration specs were causing a race condition in bolt_sips start-up when calling Bolt.Sips.start_link/0, which in turn performs a two step validation to check if Bolt.Sips.Router process exists and is alive. However, this can is error prone: if the Router process dies after the check-up, the start_link fails. So, in order to avoid integration specs setup_all block causing random failures, I've opted to force a retry whenever this occurs.