disable migrations logging while running test cases for AR schema tests
Fix query with nested array in Active Record

`User.where(id: [[1,2],3])` was equal to `User.where(id:[1, 2, 3])`
in Rails 4.1.x but because of some refactoring in Arel this stopped
working in 4.2.0. This fixes it in Rails.

[Dan Olson & Cristian Bica]
Convert string concatenations to substitutions
Prefer "if any?" to "unless empty?"

* Consistent whitespace
* Remove unnecessary parentheses
Fix warnings for undefined local variable

* Add private method primary_key_for, which more clearly shows that the
expected return value is nil when a primary key is not found.
Merge pull request #16830 from teeparham/schema_dumper

Cleanup SchemaDumper
Schema dumper: all connection adapters implement #primary_key, so rely on it exclusively
Removing unused fake models
Merge pull request #16834 from tchandy/removing_unused_fake_models

Removing unused fake models
Merge pull request #16825 from cristianbica/fix-ar-nested-arrays

Fix query with nested array in Active Record
Merge pull request #16827 from kuldeepaggarwal/f-disable-migration-logging

disable migrations logging while running test cases for AR schema tests
Do not memoize document_root_element in view tests

Memoizing will not make possible to assert the output of the view if it
is changed after the first assert_select call

Related with plataformatec/simple_form#1130 and rails/rails-dom-testing#15
Add docs for web-console to 4.2 Upgrade Guide [ci skip]
Merge pull request #16845 from todd/upgrade_guide_console_docs

Add docs for web-console to 4.2 Upgrade Guide
Remove extra 'has been' from the deprecation message

- [ci skip]
Merge pull request #16847 from prathamesh-sonpatki/kill-extra-has-been

Remove extra 'has been' from the deprecation message
Remove extra 'has been' from deprecation warning about asserting selectors

[ci skip]
Merge pull request #16848 from prathamesh-sonpatki/kill-extra-has-been

Remove extra 'has been' from deprecation warning about asserting selectors
Update upgrading guide about error handling in transactional callbacks

- Part of 16576
- [ci skip]
Merge pull request #16846 from prathamesh-sonpatki/document-error-handling-in-transactions-callbacks

Update upgrading guide about error handling in transactional callbacks [ci skip]