title: Missing theme file on Jekyll installed with RVM
body: <p>I've error when i install Jekyll on MacOS 10.13.2 with 'gem install jekyll' command:</p>
  
  <pre><code>ERROR: While executing gem ... (Gem::FilePermissionError) 
  </code></pre>
  
  <p>To solve this problem i am installed RVM and install Jekyll with RVM. Jekyll runs perfectly. But i've some critical problem here. Jekyll comes with default theme named 'Minima'. I want to customize theme, but i check site file, includes file is not here. So can't customize theme.</p>
  
  <p>To find the includes file i use that command on the terminal:</p>
  
  <pre><code>which gem minima
  </code></pre>
  
  <p>Output: </p>
  
  <pre><code>/Users/bekircem/.rvm/rubies/ruby-2.4.1/bin/gem
  </code></pre>
  
  <p>So i can't access to includes and other similiar files. </p>
  
  <p>How can i fix that problem? Any suggestions?</p>