speed up fixtures by not loading all their classes
ActiveJob: allow blank queue names

As discussed in #17195, Que uses blank queue names by default for
performance reasons. At the very least, ActiveJob should allow users to
choose "" as their queue name. This commit allows blank queue names, as
well as tests to make sure that nil queue names still use the default.
Merge pull request #17223 from bgentry/active-job-empty-queue-name

ActiveJob: allow empty queue names
tests, move `original_` var assignments outside of `begin`.
atomic_write rescue also Errno::EACCES

atomic_write rescue also Errno::EACCES on changing file permission. It could be raised with some type of filesystem
Merge pull request #17014 from grosser/grosser/fast-fixtures

speed up fixtures by not loading all their classes
Add regression test for router was overwriting PATH_INFO

[related #17233]
Default generated Gemfile to coffee-rails ~> 4.1.0
Merge pull request #17241 from josh/coffee-rails-4-1

Upgrade to coffee-rails 4.1.0
Replace Enumerable#reverse.each with Enumerable#reverse_each
Replace Array#shuffle.first with Array#sample
Start running railties builds first, since they take the longest finish
Merge pull request #17244 from sferik/reverse_each

Replace Enumerable#reverse.each with Enumerable#reverse_each
Merge pull request #17245 from sferik/sample

Replace Array#shuffle.first with Array#sample
Merge pull request #17246 from sferik/railties_first

Start running railties builds first, since they take the longest finish
Merge pull request #17234 from arthurnn/add_regression_for_path_and_cascade

Add regression test for router was overwriting PATH_INFO
fix test_helper for mountable plugin
Merge pull request #17240 from masarakki/fix-test_helper-of-mountable-plugin

fix test_helper for mountable plugin
remove unused tools/profile
Merge pull request #17247 from igas/fix-deprecations

remove unused tools/profile

We usually use moderns tools like benchmark-ips so we don't need this anymore