Restore kind_of to match using kind_of? rather than ===

Restore `kind_of(...)` to match using `kind_of?` rather than `===`

Fixes #744.
Interesting, when I first read the spec, it made sense to me as I saw it from Jon's perspective. Having read your critique, I see your perspective. I don't think one is more correct than the other. This does tell me that there is ambiguity on how this should be spec'd.

Personally, I would test both cases. I think Myron's suggestion is good. I would add the inverse though to make it clear that `kind_of?` is used over `===`.

```ruby
it 'does not match arguments where `kind_of?` is false even when `===` is true', regression: 750 do
  proxy = Object.new
  allow(proxy).to receive(:kind_of?).and_return(false)
  expect(a_double).to receive(:random_call).with(kind_of(Object))
  a_double.random_call(proxy)
end
```

I wasn't able to easily get `Fixnum` or `Numeric` to play nice with stubbing, so I used `Object`.