Fix: wrap postMessage in timeout to prevent race conditions

[AustP]

Description

There was a race condition where sometimes Kibisis wouldn't show up in the available providers. I believe this was happening because the channel was being created and a listener was being attached and then a message was immediately being posted. I've made a change so that the message being posted happens on the next tick so it actually gives the channel time to setup.

@kieranroneill

Checklist

• Code compiles correctly
• Created tests which fail without the change (if possible)
• All tests passing
• Extended the README / documentation, if necessary

[drichar]

I have noticed this happening occasionally, and the randomness of it does suggest a race condition in the initialization logic. Have you seen this before @kieranroneill ?

The issue is sporadic to begin with... that said, I can't reproduce it with your solution. So it does seem to do the trick 👍

Thank you for the PR! Sorry about the delay reviewing this and #141

[drichar]

This is approved but I'd like to see if @kieranroneill has any feedback about the issue before merging (ty in advance!)

[kieranroneill]

@drichar I will have a look at this today 😊