The problem is GitHub Pages doesn’t currently support 3rd party theme gems. Similar to how they don’t allow Jekyll plugins (except for a few that have been whitelisted). So instead of pushing commits to GH and having it build your site, you need to build it locally and push the contents of your _site folder. … A lot of people use CI services like Travis to build their site and deploy to GH.
Ohh, didn’t knew that we can’t use third party theme gems GitHub pages aren’t that clear though.
I’ll try pushing the generated _site content to GitHub to see if it works.