Include less files in the generated gem

Author: rafaelfranca

spring.gemspec

@@ -13,9 +13,8 @@ Gem::Specification.new do |gem|
   gem.homepage      = "http://github.com/rails/spring"
   gem.license       = "MIT"
 
-  gem.files         = `git ls-files`.split($/)
+  gem.files         = Dir["LICENSE.txt", "README.md", "lib/**/*", "bin/*"]
   gem.executables   = gem.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
-  gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
   gem.require_paths = ["lib"]
 
   gem.add_development_dependency 'activesupport', '~> 4.2.0'