To avoid complications with how Google Auth works, when enabling organization
multi-tenancy on a single instance, each organization becomes a "sub folder"
instead of a sub-domain.
This is basic implementation for alerts feature, where you can
define a simple rule on the last query result to send an alert.
As part of the implementation added Flask-Mail to the project,
to send emails. Should be useful to make re:dash more "self aware"
(notify users about potential issues, when queries done executing
and more).
