Only support Ruby 2.0 or newer

README.rdoc

@@ -36,7 +36,7 @@ SafeShell solves this.
 
 == Compatibility
 
-Tested with Ruby 1.8.7, but it should be happy on pretty much any Ruby version. Maybe not so much on Windows.
+Tested with Ruby 2.0.0 or newer, but it should be happy on pretty much any Ruby version. Maybe not so much on Windows.
 
 == Test
 

safe_shell.gemspec

@@ -1,4 +1,3 @@
-# -*- encoding: utf-8 -*-
 $:.push File.expand_path("../lib", __FILE__)
 require "safe_shell/version"
 
@@ -11,14 +10,15 @@ Gem::Specification.new do |s|
   s.homepage    = "http://github.com/envato/safe_shell"
   s.summary     = %q{Safely execute shell commands and get their output.}
   s.description = %q{Execute shell commands and get the resulting output, but without the security problems of Ruby’s backtick operator.}
+  s.license     = "MIT"
 
   s.add_development_dependency "rspec"
 
-  s.rubyforge_project = "safe_shell"
-
   s.files            = `git ls-files`.split("\n")
   s.test_files       = `git ls-files -- {test,spec,features}/*`.split("\n")
   s.executables      = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
   s.require_paths    = ["lib"]
   s.extra_rdoc_files = ["LICENSE", "README.rdoc"]
+
+  s.required_ruby_version = ">= 2.0.0"
 end