Remove Rspec deprecation warning

DEPRECATION WARNING: Using positional arguments in functional tests
has been deprecated, in favor of keyword arguments, and will be
removed in Rails 5.1.

Deprecated style:
get :show, { id: 1 }, nil, { notice: "Flash message" }

New keyword style:
get :show, params: { id: 1 }, flash: { notice: "Flash message" }

spec/controllers/users/confirmations_controller_spec.rb

@@ -7,7 +7,7 @@ describe Users::ConfirmationsController do
 
   describe "GET show" do
     it "returns a 404 code with a wrong token" do
-      expect { get :show, token: "non_existent" }.to raise_error ActiveRecord::RecordNotFound
+      expect { get :show, params: { token: "non_existent" } }.to raise_error ActiveRecord::RecordNotFound
     end
   end
 end