[#1] Create sendmail-trap playbook

Some servers should not be able to send email. This patch substitutes
sendmail with a script that logs email to /tmp/m.

Signed-off-by: FilmKnurd <andrew@astonishdesigns.com>
Add sendmail-trap task to example dev tasks

Signed-off-by: FilmKnurd <andrew@astonishdesigns.com>
Merge branch 'feature/1_sendmail_trapper' into dev