Improve automated email deliverability

[nathanielrindlaub]

Known deliverability issues:

1. the email address that sends out Animl invites ([email protected]) almost always gets caught in TNC's mimecast spam filter.
2. For some reason the reset password code was working for my work email but not showing up in my personal (Gmail). New user invite emails seem to work in Gmail.
3. The address is so generic it looks like spam.

[lessej]

https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-pools-add-custom-domain.html

[nathanielrindlaub]

@jue-henry also ran into a 50-email per day send limit while testing #234:

"message": "LimitExceededException: Exceeded daily email limit for the operation or the account. If a higher limit is required, please configure your user pool to use your own Amazon SES configuration for sending email.",