hw3

作業3應該是全部完成了，有些問題想請教：
☐ How to get error in html?(常常html有錯誤，卻只先顯示internal error，不知錯在哪一行)
☐ 有查到users_url(@user), which will give http://myapp.com/users/1 instead.，但似乎不work了？
☐ 在<%= link_to "here", :controller => "contacts", :action => "confirm",
    :only_path => false, :id => 17, :host => "example.com" %>，only_path的用法是？
☐ 目前信用卡付款後會附連結給使用者開，但因為是用上面的寫法，:host是寫死的，不知道如何寫比較好？
☐ what does "<<" meaning in yml for Settingslogic?
☐ In doc of Settingslogic, syck stands for what?(require 'yaml' YAML::ENGINE.yamler= 'syck')
☐ what is "||=" ?(ex. Settings.messaging['queue_name'] ||= 'user_mail')
☐ why define method with "!"?(ex. place_order!，以為是有要看error噴出來才在call method時另外加"!")
☐ 還有哪些其他情況要重開server?(ex. 安裝新的gem以後要重開才會生效) 


...v 安裝SettingsLogic v 把 key 放到 SettingsLogic 的 yml 裏⾯面 v 把 mailgun key 放到 SettingsLogic 的 yml 裏⾯面 (HEAD, origin/hw3, searchProduct, hw3) [BruceLee]

* 789667b 2014-06-30 | 用 ransack 這個 gem 實作搜尋產品功能 [BruceLee]
* 71452d0 2014-06-30 | 將CardChargesController::Create裡的動作，收納成service object: CardChargeService. (master) [BruceLee]
* fe391be 2014-06-24 | Finally fix the error updateing to mavericks [BruceLee]
* 2183b2d 2014-06-24 | Add mailgun [BruceLee]
* 7c21fd7 2014-06-23 | Use stripe to pay with credit card (origin/store-v3) [BruceLee]