Newsmedia alert delivery notifications

[PhantomWatson]

The "Here are the results of the newsmedia alert process that just completed" emails that currently get sent to me to confirm that newsmedia alerts went out without any errors should be replaced with one or both of the following options:

• These alerts get sent to Slack instead of in an email
• Emails are processed in a job queue (like what's implemented in the CRI site), which records attempted/successful deliveries

If a job queue is set up, CRI's "hey, something's wrong with the job queue" messages to Slack should be duplicated on this site too. (Or the code that sends those alerts should be moved into datacenter-plugin-cakephp3)

[ericadestoya]

Sending them to Slack would be my preferred option, just because then everyone can see the results pretty easily.