Show 'Nothing to annotate!' instead of 'Annotated ' when there are no applicable models.

lib/annotate_models.rb

@@ -143,8 +143,12 @@ module AnnotateModels
           puts "Unable to annotate #{file}: #{e.message}"
         end
       end
+      if annotated.empty?
+        puts "Nothing to annotate!"
+      else
         puts "Annotated #{annotated.join(', ')}"
       end
+    end
     
     def remove_annotations
       deannotated = []