Add step definition to add role to user
Add scenario to ensure that self-vetting is *not* possible
Disable self-vetting
Add another user in scenarios, so that idea isn't assigned to other two

The idea step def assigns the logged in user or the last user from as
the author. By creating another user, we use this recently created user as the
author.
Merge pull request #212 from HashNuke/disable_self_vetting

[Fixes #118]  Prevents self-vetting by author