Create an action for sending email

[cofiem]

This is take the impact of sending email off the web server.

The action should be very simple.

[atruskie]

I disagree with the need for this. We don't really send mass email. Only cases where this actually causes a concern is when our site is generating mass errors... in which case added complexity could destabilize the ability to even notify us of errors.

Good future option if we ever start mailing users with updates.

[atruskie]

Related to: https://github.com/QutBioacoustics/baw-private/issues/17

[atruskie]

Related to #2 and #32 - I retract my previous statement.