title: Git pages are not updating
body: <p>This has been asked before, but none of the answers seem to help. I'm using Git Pages to publish materials for a course, and the Github app to push the changes. I'm creating the website in RStudio (Index file is an .Rmd file which saves to index.html). This was working fine until today, when it suddenly stopped. None of my changes are being updated to git pages website (ending 'github.io', even though the changes are being successfully pushed to the Github Repo. None of the Github pages options has changed (index.html is saved in master/docs). There is only one branch (the 'master'), as this is a single author project. I've tried in multiple browsers. Any pointers greatly welcome!</p>