Specs for reloading the router after a change
Trigger router reload after updating route/backend
No need to reload after deleting a backend.

It can't have had any routes if deletion was allowed.
Only reload routes when enabled by ENV var.

This will be set by puppet/govuk_setenv in production, but not set by
default in development.
Merge pull request #19 from alphagov/router_reload_after_update

Trigger router reload after change.

[Delivers #59236250]