Compose ReplyToken instead of including ReplyToken
Remove whitespace for @houndci
Add 'not null' constraint and index to reply token
Remove FillInReplyTokensTransition

Removing this because we now have a not null constraint. It is
impossible to test this transition.
Default emails from team@trailmix.life
Use email reply token instead of today@trailmix
Support old emails to today@ at the same time

There are probably some folks that will take a day or so to reply to
older emails. We should support both until we don't see anyone hitting
today@trailmix.life.
Revert "Support old emails to today@ at the same time"

This reverts commit abe1d6eea4edcc1a8d251714460e0eb3288439de.