title: Travis build error: sass requires Ruby version >= 2.0.0
body: <p>So for some reason my Travis build is failed with the following error:</p>
  
  <pre><code>10.33s$ gem install sass
  Fetching: rb-fsevent-0.10.2.gem (100%)
  Successfully installed rb-fsevent-0.10.2
  Fetching: ffi-1.9.18.gem (100%)
  Building native extensions.  This could take a while...
  Successfully installed ffi-1.9.18
  Fetching: rb-inotify-0.9.10.gem (100%)
  Successfully installed rb-inotify-0.9.10
  Fetching: sass-listen-4.0.0.gem (100%)
  Successfully installed sass-listen-4.0.0
  Fetching: sass-3.5.1.gem (100%)
  ERROR:  Error installing sass:
      sass requires Ruby version &gt;= 2.0.0.
  The command "gem install sass" failed and exited with 1 during .
  </code></pre>
  
  <p>```</p>
  
  <p>My <code>travis.yml</code> file is as follows:</p>
  
  <pre><code>language: node_js
  node_js:
      - 6
  before_install:
      - gem install sass
      - gem install scss-lint
      - npm install -g grunt-cli 
  install: 
      - npm install
  before_script: 
      - grunt theme
  </code></pre>
  
  <p>```</p>
  
  <p>I even tried specifying a Ruby version greater than 2, but the error of "sass requires Ruby version >= 2.0.0" still persists:</p>
  
  <pre><code>language: node_js
  node_js:
      - 6
  before_install:
      - gem update --system 2.1.11
      - gem --version
      - gem install sass
      - gem install scss-lint
      - npm install -g grunt-cli 
   install: 
      - npm install
  before_script: 
      - grunt theme
  </code></pre>
  
  <p>I have another project with a more or less identical travis.yml file so can't for the life of me figure out what's wrong.</p>