Add release task

Rakefile

@@ -1,5 +1,8 @@
 require 'rspec/core/rake_task'
 
+base = File.dirname(__FILE__)
+require base + "/lib/capybara/poltergeist/version"
+
 task :autocompile do
   system "coffee --compile --bare --watch " \
          "--output lib/capybara/poltergeist/client/compiled " \
@@ -10,3 +13,12 @@ RSpec::Core::RakeTask.new('test') do
 end
 
 task :default => :test
+
+task :release do
+  puts "Releasing #{Capybara::Poltergeist::VERSION}, y/n?"
+  exit(1) unless STDIN.gets.chomp == "y"
+  sh "gem build poltergeist.gemspec && " \
+     "gem push poltergeist-#{Capybara::Poltergeist::VERSION}.gem && " \
+     "git tag v#{Capybara::Poltergeist::VERSION} && " \
+     "git push --tags"
+end