Sorry to add one more comment but I noticed one little thing about this. Would a better way to say this be `if EXPECTED_METHODS.any? {|m| !subject.respond_to?(m) }`?

Also, can you wrap `methods: missing_methods.to_sentence` in curly braces? I know that Ruby lets you get away with not putting them there, but it makes it a little easier to parse visually that you have a hash there.

Other than this and the gemspec change, I think we're good to go.