Implement email notifications for admins

[PatrikD]

Admins should be notified whenever a new member joins, starts or stops a payment plan, or when a credit card is bouncing (perhaps only after the 3rd failure?)

Not all admins may want to receive all these notifications, so perhaps the profile page for admins could include a series of checkboxes to sign up to these various alerts.

[PatrikD]

Do the individual members even get notified when their credit card starts bouncing? That obviously would be a must-have feature as well!

[rcsheets]

No, I don't think anyone gets notified ever. The two features are related but should probably be tracked separately.

[okdistribute]

I started a branch here that is the start to this implementation for emailing when users subscribe. https://github.com/sudoroom/sudo-humans/tree/payment-email

To find out when a payment bounces, we need to set up a Stripe webhook. Who has access to the stripe account? https://stripe.com/docs/recipes/sending-emails-for-failed-payments

[rcsheets]

I had assumed we could poll for that, but a webhook sounds like a better option.
I don't have Stripe account access, but I should, so I'll follow up on that.

[rcsheets]

I have access to Stripe now.