Prepare assets

Something to note in this pull request:

1. View files in views/static_pages are automatically served under `/pages/:page` If the view doesn't exists then it throw a Not Found error.
Test for this is incomplete because I don't know how to stub views in a controller spec.

2. The design posted earlier can be viewed in /pages/test_blog.
The test page for sir-trevor is /pages/sir-trevor
A kitchen sink of Bootstrap elements is in /pages/sink

3. I added spring for fast loading and guard to run test automatically.