This allows expire_in (and other options) to be passed to the cache method

This is no longer necessary, as the minimum version requirement for Ruby is 2.2.2, and the `caller_locations` feature was added in Ruby 2.0.0. Since Rails no longer supports pre 2.0 versions of Ruby, there is no need to check first if the Kernel does respond to `caller_locations`. The answer is: yes it does.

As per railties/lib/rails/test_unit/railtie.rb, where it sets it explicitly.

This can be confirmed by starting a new Rails console session in a new app and running this code:

Rails.application.config.app_generators.rails[:integration_tool]

I also beefed up the documentation slightly to be more explicit about what this configuration setting does.

…fy messaging around 'Showing Posts' section

I've personally seen too many newbies get this wrong and pluralize the association

This is fairly common in Rails applications and is requested a lot of the time on Stack Overflow and #rubyonrails

exercise, fix typos

…' call

…uery_ujs, which is necessary to have in application layout

…thod:

…d routes earlier

…where they're coming from

…plates

…ection