Setup gulp build task

NOTE:
Please installl gulp, gulp-pandoc and pandoc before building markdown to
rst.

```
$ npm install -g gulp
$ npm install gulp gulp-pandoc
$ brew install pandoc
$ gulp # upstart gulp watcher and builder. shut the fuck up and write some
draft!
```
Write preface and first section
Write chapter1: Route 53
No auto wrap texts
Use code block
Start writing chapter2 and re-ordering header level
Write chapter2 section1 and seciton2
Finish writing first revision
Merge pull request #8 from rosylilly/aws-to-codenize

[WIP] Codenize AWS