* Switch to keyword args where we can without breaking compat.
* Use add_table_options! for :options, too.
* Some code polish.

Fix forced cache miss for fetch when called without a block.

- Raised an argument error if no block is passed to #fetch with
'force: true' option is set.
- Added tests for the same.

Fix typos in ActionCable Channel [ci skip]

Railties' `config` method instatiates a Rails::Railtie::Configuration
object. Rails::Configuration is not used in this file.

The patch does not replace the file being required with the one for
Rails::Railtie::Configuration because that one is autoloaded. See the
spot where this patch changes double quotes with single quotes.

Rails::Railtie::Configuration does depend on Rails::Configuration, and
it requires it accordingly.

Update ActiveRecord associations documentation on :validate option [ci skip]

[ci skip] Update ActiveRecord associations documentation to avoid confusion with :validate option. Caused by #24532.

Document consistency [ci skip]

Add test to verify named unique index, when creating reference via add_reference

Introduce weeks and hours periods to Duration.

Change 1.week to create a 1 week duration instead of 7 days and 1.hour
to create a 1 hour duration instead of 3600 seconds.

Merge pull request #24603 from prathamesh-sonpatki/fix-wording-about-adapters-supporting-db-comments

Fix wording related to adapters supporting database comments [ci skip]

Add note about ability to add database comments to release notes [ci skip]

This is just to remove astonishment from getting `3600 seconds` from typing `1.hour`.

Move CHANGELOG entry about database notices at the top [ci skip]

Specify that behavior will be deprecated in Rails 5.1

Added notice when a database is successfully created or dropped.

Stop passing unused payloads to instrumentation block in cache

Properly verify that cache accepts and uses `expires` value. 

Add render allows unicode text name in partials - 🍣

Add support for specifying comments for tables, columns, and indexes in database itself

don't remove `cable.js` when a channel is removed

documentation for add_references index option [ci skip]

- Add link for finding the addional options for index.
- Add example for unique index as this is a common requirement.
- Add link in guide for index options.

Comments are specified in migrations, stored in database itself (in its schema),
and dumped into db/schema.rb file.

This allows to generate good documentation and explain columns and tables' purpose
to everyone from new developers to database administrators.

For PostgreSQL and MySQL only. SQLite does not support comments at the moment.

See docs for PostgreSQL: http://www.postgresql.org/docs/current/static/sql-comment.html
See docs for MySQL: http://dev.mysql.com/doc/refman/5.7/en/create-table.html

`cable.js` is required for other Channels.

Add TIP about app:update task in 'A Guide for Upgrading Ruby on Rails'

Add changelog for #24542

Fixed ActionCable::Connection::ClientSocketTest test