session url pattern

创建新分享 - render
`app.get('/session/create', session.new);`
创建新分享 - action
app.post('/session/create', session.create);
分享详细 - render
app.get('/session/:id/', session.detail);
编辑分享 - render
app.get('/session/:id/edit', session.edit);
编辑分享 - action
app.post('/session/:id/edit', session.update);
删除分享 - action
app.del('/session/:id/', session.del);