修改 readme 的 markdown 语法，高亮 ruby 代码

README.md

-# Igetui::Ruby
+# IGeTui::Ruby
 
 [个推](http://www.igetui.com/)服务端 ruby-sdk
 
@@ -6,102 +6,119 @@
 
 Add this line to your application's Gemfile:
 
-    gem 'igetui-ruby', require: 'IGeTui'
+```ruby
+gem 'igetui-ruby', require: 'IGeTui'
+```
 
 And then execute:
 
-    $ bundle
+```ruby
+$ bundle
+```
 
 Or install it yourself as:
 
-    $ gem install igetui-ruby
+```ruby
+$ gem install igetui-ruby
+```
 
 ## Usage
 
 ### Push Message To Single
 
-    pusher = IGeTui.pusher(your_app_id, your_app_key, your_master_secret)
+```ruby
+pusher = IGeTui.pusher(your_app_id, your_app_key, your_master_secret)
 
-    # 创建通知模板
-    template = IGeTui::NotificationTemplate.new
-    template.logo = 'push.png'
-    template.logo_url = 'http://www.igetui.com/wp-content/uploads/2013/08/logo_getui1.png'
-    template.title = '测试标题'
-    template.text = '测试文本'
+# 创建通知模板
+template = IGeTui::NotificationTemplate.new
+template.logo = 'push.png'
+template.logo_url = 'http://www.igetui.com/wp-content/uploads/2013/08/logo_getui1.png'
+template.title = '测试标题'
+template.text = '测试文本'
 
-    # 创建单体消息
-    single_message = IGeTui::SingleMessage.new
-    single_message.data = template
+# 创建单体消息
+single_message = IGeTui::SingleMessage.new
+single_message.data = template
 
-    # 创建客户端对象
-    client = IGeTui::Client.new(your_client_id)
+# 创建客户端对象
+client = IGeTui::Client.new(your_client_id)
 
-    # 发送一条通知到指定的客户端
-    ret = pusher.push_message_to_single(single_message, client)
-    p ret
+# 发送一条通知到指定的客户端
+ret = pusher.push_message_to_single(single_message, client)
+p ret
+```
 
 ### Push Message To List
 
-    pusher = IGeTui.pusher(your_app_id, your_app_key, your_master_secret)
-
-    # 创建一条透传消息
-    template = IGeTui::TransmissionTemplate.new
-    # Notice: content should be string.
-    content = {
-                action: "notification",
-                title: "标题aaa",
-                content: "内容",
-                type: "article",
-                id: "4274"
-              }
-    content = content.to_s.gsub(":", "").gsub("=>", ":")
-    template.transmission_content = content
-
-    # 创建群发消息
-    list_message = IGeTui::ListMessage.new
-    list_message.data = template
-
-    # 创建客户端对象
-    client_1 = IGeTui::Client.new(your_client_id_1)
-    client_2 = IGeTui::Client.new(your_client_id_2)
-    client_list = [client_1, client_2]
-
-    content_id = pusher.get_content_id(list_message)
-    ret = pusher.push_message_to_list(content_id, client_list)
+```ruby
+pusher = IGeTui.pusher(your_app_id, your_app_key, your_master_secret)
+
+# 创建一条透传消息
+template = IGeTui::TransmissionTemplate.new
+# Notice: content should be string.
+content = {
+            action: "notification",
+            title: "标题aaa",
+            content: "内容",
+            type: "article",
+            id: "4274"
+          }
+content = content.to_s.gsub(":", "").gsub("=>", ":")
+template.transmission_content = content
+
+# 创建群发消息
+list_message = IGeTui::ListMessage.new
+list_message.data = template
+
+# 创建客户端对象
+client_1 = IGeTui::Client.new(your_client_id_1)
+client_2 = IGeTui::Client.new(your_client_id_2)
+client_list = [client_1, client_2]
+
+content_id = pusher.get_content_id(list_message)
+ret = pusher.push_message_to_list(content_id, client_list)
+```
 
 ### Push Message To App
 
-    pusher = IGeTui.pusher(your_app_id, your_app_key, your_master_secret)
+```ruby
+pusher = IGeTui.pusher(your_app_id, your_app_key, your_master_secret)
 
-    # 创建通知模板
-    template = IGeTui::NotificationTemplate.new
-    template.logo = 'push.png'
-    template.logo_url = 'http://www.igetui.com/wp-content/uploads/2013/08/logo_getui1.png'
-    template.title = '测试标题'
-    template.text = '测试文本'
+# 创建通知模板
+template = IGeTui::NotificationTemplate.new
+template.logo = 'push.png'
+template.logo_url = 'http://www.igetui.com/wp-content/uploads/2013/08/logo_getui1.png'
+template.title = '测试标题'
+template.text = '测试文本'
 
-    # 创建APP群发消息
-    app_message = IGeTui::AppMessage.new
-    app_message.data = template
-    app_message.app_id_list = [your_app_id]
+# 创建APP群发消息
+app_message = IGeTui::AppMessage.new
+app_message.data = template
+app_message.app_id_list = [your_app_id]
 
-    # 发送一条通知到程序
-    ret = pusher.push_message_to_app(app_message)
-    p ret
+# 发送一条通知到程序
+ret = pusher.push_message_to_app(app_message)
+p ret
+```
 
 ### Custom Test
 
-    require 'rubygems'
-    require 'IGeTui'
+```ruby
+require 'rubygems'
+require 'IGeTui'
 
-    @pusher = IGeTui.pusher(your_app_id, your_app_key, your_master_secret)
-    ret = @pusher.get_client_id_status(@cid_1)
-    p ret
+@pusher = IGeTui.pusher(your_app_id, your_app_key, your_master_secret)
+ret = @pusher.get_client_id_status(@cid_1)
+p ret
+```
 
 ### Auto Test
 
-    # 运行测试之前，请先修改 test/pusher_test.rb 中的相关配置
-    rake test
+运行测试之前，请先修改 test/pusher_test.rb 中的相关配置。
+
+```ruby
+rake test
+```
 
 ## Contributing