Add the ability to release jekyll-docs with the right site.

jekyll-docs/Rakefile

@@ -1,14 +1,24 @@
-require "bundler/gem_tasks"
-task :build => :init
 task :default => :init
 
-def jekyll_version
+def name
+  "jekyll-docs".freeze
+end
+
+def gemspec_file
+  "#{name}.gemspec"
+end
+
+def gem_file
+  "#{name}-#{version}.gem"
+end
+
+def version
   ENV.fetch('JEKYLL_VERSION')
 end
 
 task :init do
   sh "git clone git://github.com/jekyll/jekyll.git jekyll" unless Dir.exist? "jekyll/.git"
-  Dir.chdir("jekyll") { sh "git checkout v#{jekyll_version}" }
+  Dir.chdir("jekyll") { sh "git checkout v#{version}" }
   rm_rf "site"
   cp_r "jekyll/site", "site"
 end
@@ -17,3 +27,29 @@ task :teardown do
   rm_rf "site"
   rm_rf "jekyll"
 end
+
+#############################################################################
+#
+# Packaging tasks
+#
+#############################################################################
+
+desc "Release #{name} v#{version}"
+task :release => :build do
+  unless `git branch` =~ /^\* master$/
+    puts "You must be on the master branch to release!"
+    exit!
+  end
+  unless `git diff`.empty?
+    puts "We cannot proceed with uncommitted changes!"
+    exit!
+  end
+  sh "gem push pkg/#{name}-#{version}.gem"
+end
+
+desc "Build #{name} v#{version} into pkg/"
+task :build => :init do
+  mkdir_p "pkg"
+  sh "gem build #{gemspec_file}"
+  sh "mv #{gem_file} pkg"
+end