Fix get billing email

getBillingEmail fails to do what it says on the tin in a number of situations.

This MR adds a test and a fix.

@artfulrobot I didn't see this... Can you make the getBillingEmail function public per your code comment - I have no problem with doing that but create functions by default with the minimal exposure so they can be "opened up" later if required.

added 1 commit

• c850e0bc - open up getBillingEmail to public so it can be tested; refactor tests

Compare with previous version

done

merged

mentioned in commit ceb46d28

Thanks @artfulrobot