[3.7] bpo-36057 Update docs and tests for ordering in collections.Counter [no behavior change] (GH-11962) by miss-islington · Pull Request #11979 · python/cpython

@rhettinger @miss-islington

…no behavior change] (pythonGH-11962)

* Add tests for Counter order.  No behavior change.

* Update docs and tests

* Fix doctest output and capitalization
(cherry picked from commit 407c734)

Co-authored-by: Raymond Hettinger <rhettinger@users.noreply.github.com>