Improved: Users can be members of multiple accounts

Previously, a single Code Climate user (as identified by a unique email address) could only be under one account. That was simple, but quickly broke down for users who worked with multiple organizaitons, especially consultancies who use Code Climate for all of their projects.

As of today, a Code Climate user can be added to multiple accounts. There’s not much to show for this feature, but account admins will no longer receive the dreaded “email is already in use by a user” error when adding their teams.