Add all matcher [DONE]

https://github.com/rspec/rspec-expectations/issues/483

- [x] add cuke
- [x] disallow the negative form for now (potentially reenable it after there's been a community discussion)
- [x] update changelog
- [x] define initialize_copy: (https://github.com/rspec/rspec-expectations/pull/518/files#diff-afbc871db3c3948bc68aca8db1cb90dbR29)
- [ ] Ensure the negation PR is ready to merge (an error message here mentions it)

**Changelog**
* Add support for `all` matcher, to allow you to match matcher on a collection.
    * `expect(stoplight.color).to ~eq("blue")`
    * `expect([1, 3, 5]).to all( be_odd.and be_an(Integer) )`
    (Adam Farhi)

as @myronmarston mentioned;
waiting for 3.1 release