Now that master points at Rails 5, we might not need to explain how
things used to work in Rails 3. Or we might… up to you 😁

[ci skip] Fix comment of `ActiveRecord::Associations#association_inst…

not needed require's

[ci skip] Fix purpose of `assert_kind_of`

- as core_ext is not used and test pass locally
- mail is already required in abstract_unit

Refactor railties console and dbconsole commands

fix minor convention problems

correct error text message in engines.md [ci skip]

promote :except option instead of :only for before action docs [ci skip]

This moves `TemplateAssertions` out of the `test_case.rb` file and into
it's own `template_assertions` file. It still inherits from
`ActionController`.`

This is in preparation for combining the code for Integration tests and
Controller tests. This will need to be it's own file to be added to the
`requires` for Integration tests. This does not currently change ANY
behavior, just moving it for access later on.

`assert_emails` in block form use the given number as expected value

minor rdoc syntax fix [ci skip]

docs: syncing with the code, adding aj [ci skip]

change GeneratedFeatureMethods to GeneratedAssociationMethods in docs

the module name was changed in 8e814a0a

Provide provider_job_id to qu adapter.

as/core_ext require's not used

Better formatted documents [ci skip]

Refactor sidekiq adapter enqueue and enqueue_at methods

Don't need to explicitly set test_order it's :random default

:nodoc: rename_column in postgresql/schema_statements.rb [ci skip]

The old `test_create_bang_returns_falsy_when_join_record_has_errors` had
a missleading name and was a duplicate of
`test_save_should_not_raise_exception_when_join_record_has_errors`.

Since it had an assertion on the return value I renamed it accordingly
and got rid of the duplicate test.

Its already doc'ed in
activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb

added activejob in list [ci skip]

Further work to provide provider_job_id for queue adapters.

Adds documentaion for the Rails.root and Rails.public_path methods