Add a template for admin pages

modified:   views/admin/layout.jade
  Use this file as a standard template for all admin pages.

modified:   routes/tellusadmin.js
  Add a route for /tellusadmin/index

new file:   test/tags.route.js
new file:   test/test.js
  Test case, but still useless.
A view for admin tag page

new file:   views/admin/tags.jade
  view for the admin page to modify tags

modified:   app.js
  add the route for /logout

modified:   routes/tags.js
  change tes responce spec, every response message should fave type and
  content.

modified:   routes/tellusadmin.js
  add the route for /tellusadmin/tags. add a middleware isAuth to check
  if user had login.
Add the bower.json
Update README.md

add a short description
Merge pull request #1 from shingo0620/master

更新了很多~恩