Add tests for ActiveModel::Serializers::JSON#as_json ordering
Avoid Skip in test, have a unified test for order
Add note about installing and running Memcached for Rails test suite tests that depend on it. [ci skip]
Split the 1200+ line mime_responds_test into 3 more focused and manageable test files.
Fail informatively in #respond_with when no appropriate #api_behavior renderer is available.

Currently if a user calls #respond_with(csvable), but has not csv
renderer available, Responder will just run through the default render
behavior twice, raising ActionView::MissingTemplate both times.

This changes ActionController::Metal::Responder#api_behavior to check
in advance whether there is a renderer available, and raise
ActionController::MissingRenderer if not.
Merge pull request #11812 from gaurish/json-order

Add tests for ActiveModel::Serializers::JSON#as_json ordering variations
Merge pull request #11926 from Empact/respond-with-csv

Fail informatively in #respond_with when no appropriate #api_behavior renderer is available.
Refactor serialization test for hash order
blorgh_engine to blorgh [ci-skip]
Merge pull request #11929 from scaryguy/master

blorgh_engine to blorgh
Dont' check for any order in hash since we aren't sorting it and this is determinated only by the used interpreter
Rename @locals to @_locals in Thread to avoid conflict with Rubinius. Closes #11831
Merge pull request #11914 from pawel2105/development-dependencies-guides-fix

Memcached note for Rails guides [ci skip]
duration is called multiple times in dev, so lets cache it
oops, I missed this in 7193f75