New matcher: `have_attributes`

see: https://github.com/rspec/rspec-expectations/issues/565

@myronmarston @JonRowe @cupakromer /cc

TODO's
- [ ] update README

not meaning to offend anyone - clearly this a troubling issue;
is there still an extra space? 
I was copying the format from:
https://github.com/rspec/rspec-expectations/blob/master/features/built_in_matchers/include.feature#L31-L53