Fix initialization for Rails 4

The current version prevents the server from starting when using Rails 4.

/Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/bundler/gems/rails-0d7b0f0183ce/railties/lib/rails.rb:37:in `configuration': undefined method `config' for nil:NilClass (NoMethodError)
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/gems/newrelic_rpm-3.5.0.1/lib/newrelic_rpm.rb:44:in `<top (required)>'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/gems/bundler-1.2.1/lib/bundler/runtime.rb:68:in `require'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/gems/bundler-1.2.1/lib/bundler/runtime.rb:68:in `block (2 levels) in require'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/gems/bundler-1.2.1/lib/bundler/runtime.rb:66:in `each'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/gems/bundler-1.2.1/lib/bundler/runtime.rb:66:in `block in require'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/gems/bundler-1.2.1/lib/bundler/runtime.rb:55:in `each'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/gems/bundler-1.2.1/lib/bundler/runtime.rb:55:in `require'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/gems/bundler-1.2.1/lib/bundler.rb:128:in `require'
	from /Users/jon/Sites/card-game/config/application.rb:11:in `<top (required)>'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/bundler/gems/rails-0d7b0f0183ce/railties/lib/rails/commands.rb:83:in `require'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/bundler/gems/rails-0d7b0f0183ce/railties/lib/rails/commands.rb:83:in `block in <top (required)>'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/bundler/gems/rails-0d7b0f0183ce/railties/lib/rails/commands.rb:80:in `tap'
	from /Users/jon/.rvm/gems/ruby-1.9.3-p0@card-game/bundler/gems/rails-0d7b0f0183ce/railties/lib/rails/commands.rb:80:in `<top (required)>'
	from script/rails:6:in `require'
	from script/rails:6:in `<main>'