Determining which files to ignore

configatron.gemspec

@@ -11,6 +11,7 @@ Gem::Specification.new do |s|
   s.email = "mark@markbates.com"
   s.extra_rdoc_files = ["LICENSE"]
   s.files = ["lib/configatron/configatron.rb", "lib/configatron/core_ext/class.rb", "lib/configatron/core_ext/kernel.rb", "lib/configatron/core_ext/object.rb", "lib/configatron/core_ext/string.rb", "lib/configatron/errors.rb", "lib/configatron/proc.rb", "lib/configatron/rails.rb", "lib/configatron/store.rb", "lib/configatron.rb", "lib/generators/configatron/install/install_generator.rb", "lib/generators/configatron/install/templates/configatron/defaults.rb", "lib/generators/configatron/install/templates/configatron/development.rb", "lib/generators/configatron/install/templates/configatron/production.rb", "lib/generators/configatron/install/templates/configatron/test.rb", "lib/generators/configatron/install/templates/initializers/configatron.rb", "README.textile", "LICENSE"]
+  ignored_files = File.read('.gitignore').split("\n").compact.reject(&:empty?) + ["Rakefile", "Gemfile", "configatron.gemspec"]
   s.homepage = "http://www.metabates.com"
   s.require_paths = ["lib"]
   s.rubyforge_project = "magrathea"