Bumped version for next release
Refactor invite accepting logic into model methods
Style nit
Fix topoff invites bug

This fixes the bug where topping off invites would
remove someone's unlimited invites.
Fix add invites bug

This fixes the bug where adding invites to a user
would set them to have unlimited invites.
Refactor email confirmed receiver to model method
Handle case where a user skips email confirmation

In DUA, if you are invited to a site and you end
up signing up with the same email address, DUA will
skip the confirmation cycle and count it as
confirmed already.
Add a joined independently signal
Update changelog