Add cc: sam@agileventures.org to mailers

Pivotal Tracker https://www.pivotaltracker.com/story/show/67381726
Only cc: added to both mailers, no refactoring.
Is it possible to avoid repetition in mailer_spec.rb?
there is no need to check for `nil`, my guess is it returns an empty array. Even if it does, it will still fail the test when calling `include?` on a `nil` object, but it is more readable. Not quite sure we need a custom matcher for something this simple, any particular reason for doing it this way?