Simplify setup (configuration and token generation)

[patcon]

Reticketed from https://github.com/ossobv/slackbridge/issues/10#issuecomment-317416030 (I had related questions)

Curious your thoughts on this!

Do you think that goal (simpler config) might involve web api anyhow? the thinking being that config could then just be "register a new app", and then it's simple in-browser oauth for two teams stored in some backend.

or we're you more thinking along the lines of a CLI wizard and envvars?

[wdoekes]

Well, for starters, begin removal of the horrendous CONFIG dict and replace with ini-file loading like this:

[DEFAULT]
WEBHOOK_IN_URL = https://hooks.slack.com/services
WEBHOOK_IN_URL_OSSO = ${WEBHOOK_IN_URL}/X/Y/Z
WEBAPI_TOKEN_OSSO = xoxp-token-token-token

[company1-osso]
A.webhook_in_url =
    ${WEBHOOK_IN_URL}/AAAAAAAAA/BBBBBBBBB/cccccccccccccccccccccccc
A.webhook_out_token = dddddddddddddddddddddddd
A.channel = CXXXXXXXX
A.peername = osso
A.webapi_token =
 
B.webhook_in_url = ${WEBHOOK_IN_URL_OSSO}
B.webhook_out_token = eeeeeeeeeeeeeeeeeeeeeeee
B.channel = #shared-company1
B.peername = company1
B.webapi_token = ${WEBAPI_TOKEN_OSSO}

Splitting it up into several files will add the need for a setup.py, but also make refactoring/testing easier.