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