Update to Rails 5.1.3

AndorChen · AndorChen · commit 3e9fdbb3f6f8 · 2017-08-08T14:02:09.000+08:00
diff --git a/source/zh-CN/initialization.md b/source/zh-CN/initialization.md
@@ -97,7 +97,7 @@ require 'bundler/setup' # 设置 Gemfile 中列出的所有 gem
 *   arel
 *   builder
 *   bundler
-*   erubis
+*   erubi
 *   i18n
 *   mail
 *   mime-types
