Bug #1703721 - combine add user tests and make more comprehensive

Removes 3 existing tests and replaces with one Adds 2 new csv files
-fixed domain names so they are all example.org
-changed one domain to example.com for use in add_users_new test
as mahara doesn't like .org.
Indentation and Captalisation changes done.

Change-Id: I0c767c5736c613d3d82b20a59014015db8ea6071