First cut of email verification feature.

This is a work in progress
 - User sends 'i am blah' via DM
 - Bot sends email to that account
 - Currently email sending is in utils, need to move this to tasks (for
   async)
 - Need to figure out how to deal with dupe codes (can't trust random
   number generators)
 - Still need to receive code via DM and 'verify' account
 - More testing!
Improvements to verify_email

Need to pre-populate email addresses or this will fail
Added more test data
Still a WIP