Avoid lots of queries to load organisations.
Avoid lots of queries to load organisations.

This happens when calling `to_s` on every `MinisterialRole` loaded, as is the case when generating the `select` element in the document edit view. Including `organisations` in the query that's used in this specific case is an unobtrusive solution; in the future we might want to always load organisations with ministerial roles.

askl56/whitehall,YOTOV-LIMITED/whitehall,hotvulcan/whitehall,hotvulcan/whitehall,ggoral/whitehall,YOTOV-LIMITED/whitehall,ggoral/whitehall,askl56/whitehall,alphagov/whitehall,ggoral/whitehall,alphagov/whitehall,askl56/whitehall,alphagov/whitehall,robinwhittleton/whitehall,YOTOV-LIMITED/whitehall,hotvulcan/whitehall,YOTOV-LIMITED/whitehall,robinwhittleton/whitehall,robinwhittleton/whitehall,alphagov/whitehall,askl56/whitehall,robinwhittleton/whitehall,ggoral/whitehall,hotvulcan/whitehall