Implement possibility to build static demo

[kvolkovich-sc]

Goal

Implement possibility to build static site with demo.
It useful for publish demo to GitHub pages like here.

Now it implemented with shell scripts:

• generate
• deploy

API

showroom-config.js

{
...
output: "showroom-demo", // build demo page and place static files to *.gh-pages* directory
tarball: "showroom-demo.tar.gz", // make additional archive with demo page
repository: "<repository_url>", // Publish to <repository_url>/.gh-pages branch
directoryPerBranch: true, // publish each demo-page files to separate dir named as branch
forcePublish: true // use git push --force (for .gh-pages branch)
...
}

npm sctipts

showroom build
showroom deploy

First need to implement #9