Pass options to backend

[davedoesdev]

When publishing message, pass qos, clientId and messageId to ascoltatore.
When forwarding message, pass on qos and messageId to client.
When subscribing, pass qos to asoltatore.
Close ascoltatore when server is closed.
Tests for passing on qos and messageId.
Update ascoltatori dependency to 0.5.0.

[mcollina]

Cool! I've just noticed there is a problem on Ascoltatori.
At this line https://github.com/mcollina/ascoltatori/blob/master/lib/mqtt_ascoltatore.js#L90 we are checking if there is already a subscription for that topic. However, we are not checking QOS levels, so we may have an old qos 0 subscription masquerading a 'new' qos 1.
As these are unrelated, do you need this in Mosca to add a couple of tests for Ascoltatori, right?

[davedoesdev]

Good catch. Yes, adding this pull request is independent and then I can write a test in Ascoltatori to make two subscriptions and check we get messages with the appropriate QoS.
I'll also write a test mirroring the one that's already in memory_ascoltatore_spec.js ("should publish with options").

[davedoesdev]

Let me know when you get time to merge it and then I'll do those Ascoltatori tests

[mcollina]

Published to npm!

[mcollina]

Thanks again 🍻