Installer uses new ruby syntax for adding Spree root mount point

core/lib/generators/spree/install/install_generator.rb

@@ -167,15 +167,15 @@ def notify_about_routes
   # If you would like to change where this engine is mounted, simply change the :at option to something different.
   #
   # We ask that you don't use the :as option here, as Spree relies on it being the default of "spree"
-  mount Spree::Core::Engine, :at => '/'
+  mount Spree::Core::Engine, at: '/'
         }
       end
 
       unless options[:quiet]
         puts "*" * 50
         puts "We added the following line to your application's config/routes.rb file:"
         puts " "
-        puts "    mount Spree::Core::Engine, :at => '/'"
+        puts "    mount Spree::Core::Engine, at: '/'"
       end
     end