Optionally threading posts to parent topic in slack integration

[mcdanlj]

I’ve cleaned up the PR a lot but it’s not quite yet ready to go. I have two or three things so far causing me trouble that I don’t yet know how to fix.

1. I’m trying to use fa-arrow-circle-o-right as my thread icon, and it is showing up empty in the UI on my live site. (I’ve been running su discourse -c 'bundle exec rake assets:precompile' && sv restart unicorn after checking out my branch on my live site to test on the live server.) I’ve added it to plugin.rb as well as referencing it, so I’m lost on what next steps are. Is there a list of fontawesome icons that are approved for use in Discourse? Found lib/svg_sprite/svg_sprite.rb and chevron-right looks great for this use.

2. Tests are all passing for me locally, but in Travis I’m getting consistent errors that appear unrelated to my changes, and naturally that’s hard for me to investigate or reason about. 13 failures with a 404 instead of some other expected (e.g. 200) in spec/lib/discourse_chat/provider/slack/slack_command_controller_spec.rb Fixed by not cargo-coding isolate_namespace and now I know about rake routes

I’ve successfully posted:

There might be more to clean up, but I think this works.

After this merges, I’ll update Chatroom Integration Plugin (discourse-chat-integration) appropriately.