title: Jekyll theme does not work on GitHub Pages but works locally
body: <p>I've been struggling with this for a few hours now, to no avail. I'm trying to use one of the <em>supported</em> GitHub Pages themes (Cayman) in my docs site and I'm having a ton of trouble. The site looks great when I run it locally using <code>bundle exec jekyll serve --safe</code> (I read that GitHub uses the safe flag) but on GitHub it doesn't show any theme.</p>
  
  <p>Gemfile:</p>
  
  <pre><code>source "https://rubygems.org"
  gem "github-pages", group: :jekyll_plugins
  gem "tzinfo-data", platforms: [:mingw, :mswin, :x64_mingw, :jruby]
  </code></pre>
  
  <p>_config.yml:</p>
  
  <pre><code>title: myproject
  baseurl: "/myproject"
  url: ""
  markdown: kramdown
  theme: jekyll-theme-cayman
  exclude: [vendor]
  </code></pre>
  
  <p>index.md:</p>
  
  <pre><code>---
  layout: default
  ---
  This is the home page of the myproject documentation.
  </code></pre>
  
  <p>The site appears fine when run locally, but the version on GitHub Pages (<a href="https://myusername.github.io/myproject" rel="noreferrer">https://myusername.github.io/myproject</a>) has no theme. Any ideas?</p>
  
  <p><strong>UPDATE:</strong><br>
  It seems as though the site is not reloading the <code>_config.yml</code>. I changed multiple settings (such as the title) and still have not seen the changes reflected in the github page, but they are reflected locally. I have also disabled caching on that page, so it is not loading an old version. GitHub says it is rebuilding the site next to each commit, and changes to the markdown show up, just not the <code>_config.yml</code>.</p>