Cleanup cuke.

- Fix odd line breaks.
- Remove unneeded `require 'rspec'`. The rspec gem
  contains no code, just dependency declarations on
  rspec-core, rspec-mocks and rspec-expectations.
Cleanup `deep_hash_dup` a bit.

- Prefer `klass === obj` over `obj.is_a? klass`.
  This is preferred because with user objects we
  generally can't trust `is_a?` as they may have
  redefined it to do something else. Redefining
  `Array.===` or `Hash.===` is much less likely.
- Rename the arg to `object` since it may not be
  a hash.
Prevent unwanted output to stdout/stderr.

These specs were calling reporter methods to
simulate examples completing, which in turn caused
printed output.
Merge pull request #1731 from rspec/pr-1706-followups

Pr 1706 followups