slackr: Output R expressions to a Slack channel/user
Description
Takes an expr, evaluates it and sends the output to a Slack
chat destination. Useful for logging, messaging on long compute tasks or
general information sharing.
what emoji to use (chr) "" will mean use the default
bot_user_oauth_token
Slack bot user OAuth token
Details
By default, everything but expr will be looked for in a "SLACK_"
environment variable. You can override or just specify these values directly instead,
but it's probably better to call slackr_setup first.