Multiple reminders for the same standup

[mgwalker]

As a user, I want standup-bot to remind me at multiple times so that users on opposite sides of the country get timely reminders.

[stvnrlly]

I was thinking about different levels of reminders, too: a day-starting "i'm here if you need me" post so that people can emoji something easily, and then a @-message reminder closer to the report time.