Add Rails::VERSION module to test monkey-patches

rspec-rails (or more specifically RailsExampleGroup) expects the
new Rails::VERSION module to exist. We could restrict the rspec-rails
version but that's probably asking for more problems in the long
run.

Before this commit, tests using rspec-rails 2.13.x failed with:

/gems/rspec-rails-2.13.2/lib/rspec/rails/example/rails_example_group.rb:10:in
`<module:RailsExampleGroup>': uninitialized constant Rails::VERSION (NameError)
Merge pull request #28 from injekt/rails-version-module

Add Rails::VERSION module to test monkey-patches
Update dependencies

Hopefully this might fix the build, it works for me locally.
stop supporting ruby 1.8
Allow default rails interface to controller functional test methods when testing unfocused controllers
Merge pull request #30 from timcowlishaw/feature_allow_default_controller_test_behaviour

Allow default rails interface in functional tests of controllers
Ease actionpack version