Handle multiple partners getting passed in.

I don’t see where this is actually used, but the old code supported it, so I’m not comfortable removing support for it without more testing.
Merge branch 'INFO-185__api_changes_fo_sp' of github.com:CruGlobal/infobase into INFO-185__api_changes_fo_sp

Conflicts:
	app/controllers/api/v1/statistics_controller.rb
Merge branch 'INFO-185__api_changes_fo_sp'