Support for alternative slack autocomplete syntax

[cakejelly]

I just noticed this when following your Mathbot tutorial. @mathbot: calculate works but mathbot: calculate doesn't.

The syntax for the second command can be a result of slacks autocomplete (unless you switch it off) and you need to explicitly add it as an alias to get it working. Can we support this by default?

[dblock]

I believe I had implemented this in dblock@80e2321, but haven't updated mathbot. Can you please try this with HEAD of slack-ruby-bot on mathbot to confirm? I can release 0.4.4 shortly if that works.

[cakejelly]

80e2321 allows you to address your bot via @<botname>... but if you begin typing your bots name without '@' and press tab, the following text will be entered: <botname>:.This isn't picked up as a valid alias. Instead, it recognises <botname> as the alias and treats everything else as your command, resulting in Sorry @cakejelly, I don't understand that command!

Currently i'm using the following as a workaround:

SlackRubyBot.configure do |config|
  config.aliases = ['mathbot:']
end

I only took a brief look at the code, but I think adding "#{user}:" to names (https://github.com/dblock/slack-ruby-bot/blob/master/lib/slack-ruby-bot/config.rb#L13) could solve this

[dblock]

Yep, do you want to try a PR with a test?

[cakejelly]

Yeah will do :) Will try get one up later on.

[dblock]

Implemented in dblock@715ff28.