Add jekyll support

[vinkla]

Added Jekyll support.

• Moved the CSS into a SASS file. The CSS is now compressed.
• Added SEO plugin for better sharing on Facebook and Twitter.
• Added Travis tests for the Jekyll integration.
• Added .editorconfig file.

To run it locally make sure you've ruby and run:

bundle install; bundle exec jekyll serve;

The biggest feature here is the support of Twitter cards and Facebook meta tags. Here is an example of Twitter cards.

[ghost]

Thanks for adding this, but I'd like to keep the site buliding a simple as possible (i.e. just a plain ol' HTML file) so I'm not to keen on introducing build steps where previously there were none. However, I am interested in the other items. I'm not much of a social media guy myself, but I assume there is also a way to get them working without Jekyll?

[vinkla]

Sure thing. I can make another pull request.

[vinkla]

@Gert-dev do you have a Twitter account? It is useful for the Twitter cards.