New exported function get_shinyslack_team_id() provides the team id for the Slack workspace used for login.
Breaking: Removed slack_shiny_ui() from exports.
Breaking: The site url is now automatically determined, so site_url is no longer an argument to any function.
Breaking: The "real" ui is no longer automatically wrapped in a cookie handler. Many UIs that use shinyslack won't need to deal with cookies in the normal app, so we shouldn't add extra, unnecessary javascript.