Remove instance writer for facet definitions
Remove instance writer for facet definitions

No need for to overwriting facet definitions on a model instance.

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