Remove unnecessary flatten! method call.
The correct status to test should be :switching_protocols.
Convert source to string if it is present.
Merge pull request #15311 from zuhao/refactor_actionpack_bare_metal_test

The correct status to test should be :switching_protocols.
Merge pull request #15312 from JuanitoFatas/action_view/asset_path

Convert source to string if it is present.
[ci skip] Update GFM link in guides guidelines.

Also remove a duplicated sentence.
Merge pull request #15315 from JuanitoFatas/guides-guidelines

[ci skip] Update GFM link in guides guidelines.
Fix test cases for inflector.rb
`yield` was missing in #with_dup, due to which 57 assertions were not running
in real, and all tests were passing by default.
Error was introduced in commit - 31ceb5e.
simple solution that brings rake stats task to every kind of rails project
Merge pull request #15310 from tgxworld/small_refactor_get_routes_as_head

Remove unnecessary flatten! method call.
Remove duplicated to_s method call.
remove unused variable warning
`warning: assigned but unused variable - album`
Fix docs for ActionController::Renderers.add
Merge pull request #15328 from kuldeepaggarwal/remove-warnings

remove unused variable warning.
Merge pull request #15324 from andriytyurnikov/simple_rake_stats_for_everything

simple solution that brings rake stats task to all rails project
Merge pull request #15316 from akshay-vishnoi/test-cases

Fix test cases for inflector.rb
Merge pull request #15325 from tgxworld/no_need_to_call_to_s

Remove duplicated to_s method call.
pg, remove unused code. Use `extract_schema_and_table` instead.
pg, add missing `:nodoc:` to adapter.
Add an interface for type objects to control Ruby => SQL

Adds the ability to save custom types, which type cast to non-primitive
ruby objects.