Update specs to new rspec syntax

spec/routing/options_requests_spec.rb

@@ -2,10 +2,11 @@ require 'spec_helper'
 
 describe '/api OPTIONS requests routing' do
   it 'routes to API::ApplicationController#cor_preflight' do
-    { options: '/api/some_route' }.should route_to(
-      controller: 'api/application',
-      action: 'cor_preflight',
-      all: 'some_route'
-    )
+    expect({ options: '/api/some_route' })
+      .to route_to(
+        controller: 'api/application',
+        action: 'cor_preflight',
+        all: 'some_route'
+      )
   end
 end