Add gems: github-pages jekyll-redirect-from

Closes #8
Add gem: rouge

Closes #9
Code cleanup - Collaboration & Disk Usage

 - Put each gem and apt package on a new line
 - Prune apt cache for smaller space on disk
 - Sort packages alphabetically

Closes #10
Added port forwarding in the jekyll alias to expose port 4000 to the host.

Closes #6.
Merge pull request #12 from thachmai/issue6

Expose port 4000 to the host with the jekyll alias
I don't do anything novel here.