fixes https://github.com/TryGhost/Team/issues/2560
When an email fails, and you reschedule the post, the error dialog was
shown (from the previous try). The retry button on that page allowed you
to retry sending the email immediately, which could be very confusing.
- The email error dialog is no longer shown for scheduled emails
- The email status is no longer polled for scheduled emails
- Retrying an email is not possible via the API if the post status is
not published or sent
- Added some extra snapshot tests
- When retrying an email, we immediately update the email status to
'pending' to have a better API response (instead of still returning
failed).
- Disabled email sending retrying in development (otherwise very hard to
test failed emails if it takes 10 mins before it gives up automatic
retrying)
refs https://github.com/TryGhost/Team/issues/1586
- updated `?newsletter_id=id` handling in posts API mock to match the real `?newsletter=slug` behaviour
- added additional publish flow acceptance tests for single/multiple newsletter behaviour, scheduling, and sending
