fixed for layout/_partial/archive.ejs

Change line 21
        <% page.each(function(item){ %>
into
        <% page.posts.each(function(item){ %>
to fix the problem that I faced for 
> Object #<Object> has no method 'each'
    at eval (eval at <anonymous> (/Users/Jeremy/Dropbox/github/scottfengjian.github.com/node_modules/hexo-renderer-ejs/node_modules/ejs/lib/ejs.js:242:14), <anonymous>:37:523)
    at eval (eval at <anonymous> (/Users/Jeremy/Dropbox/github/scottfengjian.github.com/node_modules/hexo-renderer-ejs/node_modules/ejs/lib/ejs.js:242:14), <anonymous>:37:1751)
    at /Users/Jeremy/Dropbox/github/scottfengjian.github.com/node_modules/hexo-renderer-ejs/node_modules/ejs/lib/ejs.js:255:15
    at Object.exports.render (/Users/Jeremy/Dropbox/github/scottfengjian.github.com/node_modules/hexo-renderer-ejs/node_modules/ejs/lib/ejs.js:293:13)
    at /Users/Jeremy/Dropbox/github/scottfengjian.github.com/node_modules/hexo-renderer-ejs/index.js:5:14
    at Object.exports.renderSync (/usr/local/lib/node_modules/hexo/lib/core/render.js:133:12)
    at View.renderSync (/usr/local/lib/node_modules/hexo/lib/theme/view.js:183:28)
    at partial (/usr/local/lib/node_modules/hexo/lib/plugins/helper/partial.js:29:17)
    at Object.module.exports (/usr/local/lib/node_modules/hexo/lib/plugins/helper/partial.js:37:12)
    at eval (eval at <anonymous> (/Users/Jeremy/Dropbox/github/scottfengjian.github.com/node_modules/hexo-renderer-ejs/node_modules/ejs/lib/ejs.js:242:14), <anonymous>:29:35)