Pagination improvements (#1445)

* Replace will_paginate with kaminari

* Use #page instead of #paginate in controllers

* Replace will_paginate.page_gap with pagination.truncate in i18n

* Customize kaminari views to match prior styles

* Set kaminari options to match prior behavior

* Replace will_paginate with paginate in views

config/locales/zh-CN.yml

@@ -150,5 +150,3 @@ zh-CN:
   users:
     invalid_email: 无效的邮箱
     invalid_otp_token: 无效的两步验证码
-  will_paginate:
-    page_gap: "…"