This is a follow-up to #19257

Rails 5.0 needs ruby 2.2.1 or higher

Since there was a bug in 2.2.0, the minimum ruby requirement is 2.2.1. See https://github.com/rails/rails/commit/8ed0b89b
[skip ci]

Fix rollback of frozen records

Doc fixes [ci skip]

Doc fix [ci skip]

update integration test example as is not output deprecation warning [ci skip]

[ci skip] Fix `AS` and `AR` to full name

Doc fix [ci skip]

 Fix documentation of url_for module [ci skip]

Doc fix [ci skip]

The filter was set on the pseudo-global TestAdapter but not restored to
its original value.

See e818f657

 Updated documentation of CollectionProxy#clear [ci skip]

 - CollectionProxy#clear method calls delete_all so the SQL is directly
   run into the database.
 - So the updated_at column of the object on which its run is not
   updated.
 - Closes #17161

 - The request needs to be instance of ActionDispatch::Request or an
   object that responds to host, optional_port, protocol and
   symbolized_path_parameter.
 - This documentation was correctly added in
   https://github.com/rails/rails/commit/e3b3f416b57f5642ea25078485f7e9394ad04526
   but was changed to
   https://github.com/rails/rails/commit/e1ceae576e3911f3e6708b5d19a0e3ef63769eb7.
 - Fixes #16160.

Run all our tests in random order

Using a subclass to check the sequence name does not work in that case.
The sequence name will be calucalted based on the base class.

This reverts commit ff18049c.

This broke the AR build for every adapter:

      1) Error:
    AssociationCallbacksTest#test_dont_add_if_before_callback_raises_exception:
    Exception: You can't add a post

      2) Failure:
    QueryCacheTest#test_query_cache_doesnt_leak_cached_results_of_rolled_back_queries [/Users/senny/Projects/rails/activerecord/test/cases/query_cache_test.rb:235]:
    Expected: 1
      Actual: 0

I'm reverting to get the build green again.

This entry now lives in the Action View's changelog ; refs 8a3bd089.

prompted by #19221.

Fixed ActiveJob integration tests

Closes #19227.

[ci skip] Update documentation for Time#seconds_since_midnight

`CallbackSequence#call` can only ever take one argument. Using `*args`
here produces unnecessary array allocations. Since it only ever takes
one argument we should use `arg` instead of `*args`.

This way we can get the relative_url_root from the application without
setting another global value

[ci skip] Delete excess white in documentation