Use config.token and config.aliases if set

[wasabigeek]

Fixes #240.

I assumed that setting the config in code would take precedence over an ENV variable.

Will do a separate PR for aliases after this!

[wasabigeek]

This pattern deviates from the existing, but I do feel it makes the tests more isolated from the setup in spec_helper. What do you think @dblock?

[dblock]

I like it.

[dblock]

Let's also allow passing the token in the constructor for Server in options?

[wasabigeek]

passing the token in the constructor for Server in options

Stopped short of this, some questions:

• were there any particular use cases you had in mind for letting each Server instance have it's own token? e.g. different slack bots running on the same server, but for the same team (since team would still be a global config, unless we do something there too)?
• it seems like the token doesn't actually get used in Server (it gets passed down to Client, but Client doesn't use it, I suppose because Slack requires the config to be set globally), is that intentional? (Though fixing that should probably be a separate PR anyway)

[dblock]

passing the token in the constructor for Server in options

Stopped short of this, some questions:

• were there any particular use cases you had in mind for letting each Server instance have it's own token? e.g. different slack bots running on the same server, but for the same team (since team would still be a global config, unless we do something there too)?

It's more of a best practice thing, we can have a singleton, but not globals where it's unnecessary. I don't have a better scenario, but for testing alone it's worth it IMHO.

• it seems like the token doesn't actually get used in Server (it gets passed down to Client, but Client doesn't use it, I suppose because Slack requires the config to be set globally), is that intentional? (Though fixing that should probably be a separate PR anyway)

We possibly have issues here, but I am not sure. The thing is that most people use this library with slack-ruby-bot-server, that doesn't use any of these globals and creates a bot instance with a token following an OAuth workflow. The globals were a facility to run a single bot for a single team with a token, which is deprecated by slack. Feel free to fix all/some/none! And greatly appreciate it and happy to help.

[dblock]

This looks great. A few more asks, thanks for hanging in here with me.