List of potentionally useful information that can be obtained with SLACK API calls:
* channels.history:
  * list of all messages, events
  * timestamps of these messages
* users.info:
  * name, real name, team name, e-mail
  * info about user being admin, owner, bot, restriced/ultra-restricted
* channels.info:
  * all members
  * scope of the channel (private, public, mpim..)
  * latest message
  * number of unread messages
  * topic
  * previous names