Don't set nil JSON.create_id as it's unnecessary in recent versions of the JSON library

[loganhasson]

Remove JSON.create_id = nil as it is no longer required with the current JSON lib in Ruby. (That line also broke if Oj was used as the JSON parser, as it requires a string argument.)

[olleolleolle]

@loganhasson With a rebase, this would probably be an improvement to what's in master now.

• minimum Ruby req is up to >= 2.1 now

[loganhasson]

@olleolleolle rebased and squashed :)

[olleolleolle]

@loganhasson Perhaps re-title the PR to make it prettier in merges, when that happens?

[olleolleolle]

@loganhasson Hi again!

To ease merging this PR: reduce "friction" by not changing the lib/chef-api/version.rb or CHANGELOG.md.

Updating those is another process, for the maintainer to do. Some automated tool probably bumps the version number. And the changelog is amended when the maintainer is good and ready for it.

Your CHANGELOG.md text line is explicit and descriptive. If you use that text in the title of this PR, an automated tool can put it in the changelog file.

Hope this helps!