Remove rack-test git dependency

The dependency was introduced in this commit:

002713c64568114f3754799acc0723ea0d442f7a

which has been released a long time ago
jquery-rails 2.2.1 was released
I released 0.0.3 some time ago
ar-deprecated_finders is already in the gemspec
sprockets 2.0.0.rc3 is in rails gemspec already
AR loads activerecord-deprecated_finders, no need to add it to the Gemfile
typo
Remove sprockets-rails from the Gemfile generator
Merge pull request #9420 from robertomiranda/remove-sprockets-rails

Remove sprockets-rails from the Gemfile generator
removes redundant require

It turns out this file is required in active_record.rb.
Bump sass-rails and coffee-rails to 4.0.0.beta1 in Gemfile
Are was release
Add `rails test` command to run the test suite

To run the whole test suite:

    $ rails test

To run the test file(s):

    $ rails test test/unit/foo_test.rb [test/unit/bar_test.rb ...]

To run the test suite

    $ rails test [models,helpers,units,controllers,mailers,...]

For more information, see `rails test --help`.

This command will eventually replacing `rake test:*`, and `rake test`
command will actually invoking `rails test` instead.
Update testing documentation

* Update test invocation to use `rails test` instead.
* Update all the test command previews (since we're now using MiniTest.)
* Mentioning MiniTest instead of Test::Unit.
* Update list of test suites.
Add support for MiniTest flags in TestRunner

Any flags that got set will be passed through to MiniTest::Unit.runner,
such as `-n`, `-s-, and `-v`.
Load fixtures only when running suites, or `-f`

* `rails test -f` will run the test suites with all fixtures loaded
* New application will now generated without `fixtures :all` line
  enabled by default.
Improve wording for rails test command
Update Rake tasks to call `rails test` instead

Also, print out deprecation warning for other rake tasks except
`rake test` and `rake` (default)