- Adds RedisAdapterTest::AlternateConfiguration to account
  for a relatively common alternative setup, as it’s used
  as the first example in the
  [Redis rubygem](https://github.com/redis/redis-rb#getting-started)

- Supplies original RedisAdapterTest with more complete
  redis:// url format by adding a ‘userinfo’ (blank user),
  so that it resembles the alternate configuration

- Supplies original EventedRedisAdapterTest with more complete
  redis:// url as well

- Adds before_script to start redis-server with password as a daemon
  and with explicit defaults copied from the default redis.conf
  (Instead of using Travis' default init/upstart scripts for `redis` service)

http://jruby.org/2017/06/15/jruby-9-1-12-0.html

http://jruby.org/2017/05/25/jruby-9-1-10-0.html

This version lock added by 3d890b66.
But original issue is fixed with bundler 1.15.

Ref: https://github.com/rubygems/rubygems/issues/1911#issuecomment-300148516

http://jruby.org/2017/05/16/jruby-9-1-9-0

It's causing a test to fail, and we're not yet sure what (if anything)
we should be doing differently. See rubygems/rubygems#1911.

Revert "Merge pull request #27636 from mtsmfm/disable-referential-integrity-without-superuser-privilege-take-2"

This reverts commit c1faca63, reversing
changes made to 8c658a0e.

See https://github.com/rails/rails/pull/27636#issuecomment-297534129

Also, explicitly apply the order: generate_subscripts is unlikely to
start returning values out of order, but we should still be clear about
what we want.

Related #28532, #27636

https://www.ruby-lang.org/en/news/2017/03/30/ruby-2-3-4-released/

https://www.ruby-lang.org/en/news/2017/03/28/ruby-2-2-7-released/

Re-create https://github.com/rails/rails/pull/21233

eeac6151 was reverted (127509c0) because it breaks tests.

----------------

ref: 72c15572

- We must use `authors` fixture with `author_addresses` because of its foreign key constraint.
- Tests require PostgreSQL >= 9.4.2 because it had a bug about `ALTER CONSTRAINTS` and fixed in 9.4.2.

https://www.ruby-lang.org/en/news/2017/03/22/ruby-2-4-1-released/

* Move system tests back into Action Pack
* Rename `ActionSystemTest` to `ActionDispatch::SystemTestCase`
* Remove private base module and only make file for public
`SystemTestCase` class, name private module `SystemTesting`
* Rename `ActionSystemTestCase` to `ApplicationSystemTestCase`
* Update corresponding documentation and guides
* Delete old `ActionSystemTest` files

Renames `Rails::SystemTestCase` to `ActionSystemTest` and moves it to a
gem under the Rails name.

We need to name the class `ActionSystemTestCase` because the gem expects
a module but tests themselves expect a class.

Adds MIT-LICENSE, CHANGELOG, and README for the future.

And let's see if it still fails...

Revert "Merge pull request #21233 from mtsmfm/disable-referential-integrity-without-superuser-privileges"

This reverts commit eeac6151, reversing
changes made to 5c40239d.

Reason: Broke the isolated tests.
https://travis-ci.org/rails/rails/builds/188721346

* Run actionpack and actioncable tests together
* Demote ac:integration to allow_failures -- it works most of the time,
  but still fails too frequently to rely upon

ref: 72c15572

- We must use `authors` fixture with `author_addresses` because of its foreign key constraint.
- Tests require PostgreSQL >= 9.4.2 because it had a bug about `ALTER CONSTRAINTS` and fixed in 9.4.2.

2.3.2 has a known regression https://bugs.ruby-lang.org/issues/12920#note-5

All tests pass for me locally.

All tests passing locally for me:

```
195 runs, 441 assertions, 0 failures, 0 errors, 0 skips
```

- We were running into issues with old bundler versions on 4.2
  builds. So we bumped the bundler version on 4-2-stable branch in
  https://github.com/rails/rails/pull/26592.
- This commit applies same change to master as per discussion in
  https://github.com/rails/rails/pull/26592#issuecomment-254026755.

This reverts commit 2d6c14bc.