Clear parliament instance before and after example
Clear parliament instance before and after example

The spec was picking up cached instances from other specs so wasn't
calling `last_or_create` to get our stubbed instance.

unboxed/e-petitions,joelanman/e-petitions,unboxed/e-petitions,StatesOfJersey/e-petitions,joelanman/e-petitions,unboxed/e-petitions,StatesOfJersey/e-petitions,alphagov/e-petitions,StatesOfJersey/e-petitions,unboxed/e-petitions,oskarpearson/e-petitions,alphagov/e-petitions,oskarpearson/e-petitions,oskarpearson/e-petitions,joelanman/e-petitions,alphagov/e-petitions,StatesOfJersey/e-petitions,alphagov/e-petitions