Bundle a chat-ops bot

From the direction page, we want to bundle a chat-ops bot.

Attempt to bundle Hubot was done in !564 (closed) .

Lita is another option.

Since that MR is not progressing, I am re-opening the discussion about Hubot vs. Lita.

Hubot:

  1. Needs nodejs (already in the package)
  2. Widely used by users, large community
  3. Has a large number of plugins
  4. Has Rocket.chat and Mattermost plugins
  5. Getting it up and running seems simple, documentation

Lita:

  1. Written in Ruby
  2. Plugins are rubygems
  3. Doesn't have Mattermost or Rocket.chat plugins (that I was able to find)
  4. Requires connection with Redis, makes configuration a bit more complex,documentation

The WIP MR needs a bit more work to get it over the edge, but the general concept will work within the package. To move it forward I think we should create a project that would contain all the plugins we want to support, that would give us more control over versions and plugins.

@dblessing @brodock You've been advocating for Lita more, am I missing something that we should consider as a pro for bundling Lita?

cc @stanhu @DouweM @JobV @sytses