Send donation receipt emails

[begedin]

Problem

When the user successfully donates, they need to be sent a receipt. My guess is, this should happen when a charge succeeds, meaning they get a receipt every month.

Subtasks

• add a “receipt” email to lib/code_corps/emails/receipt
• replace config :code_corps, CodeCorps.Mailer, adapter: Bamboo.LocalAdapter with PostMark adapter - Add Postmark adapter for Bamboo emails #660
• setup postmark account for production and maybe staging? (edited)
• make postmark template
• probably remove existing mailer test, replace with test for receipt
• setup test env to use test adapter
• make test work
• dev env can still use local adapter, we need to see if it works with postmark (since postmark does templates), see if “sent_emails” endpoint works
• either when handling invoice.payment_succeeded, or charge.succeeded, send the receipt email to the user who performed it. Should probably put that in the event handler itself, not the service which updates the database. Seems more fitting
• Add test to check if that happens.

[joshsmith]

Closed by #661.