Run scap when config or code is updated

Implement my hand-built beta-scap-eqiad job using JJB. Trigger it to run
during each run of beta-mediawiki-config-update or beta-code-update.

Additional changes made to existing jobs:
; beta-mediawiki-config-update
: Changed defaults from use-zuul to beta as suggested in existing
  comment.
: Removed scm override since no default is now in use.
: Replaced inline script with puppet managed shell script
: Send email to qa@lists.wikimedia.org on failure
; beta-code-update
: Changed daysToKeep and cron trigger to match existing job config on
  Jenkins instance.
: Send email to qa@lists.wikimedia.org on failure

Change-Id: I8b3a57d12074c841fba0f59c3e7078e67d689292