title: Gulp missing the SASS executable
body: <p>I'm working with gulp, I'm trying to install packages and the only way to install gulp on windows is to type npm install -g gulp@3.8.7 because new versions print me in the console some errors about the v8flags package. 
  So I'm trying to compile sass through Gulp. I've a gulpfile.js:</p>
  
  <pre><code>'use strict';
  
  var gulp = require('gulp');
  var sass = require('gulp-ruby-sass');
  
  gulp.task('sass', function() {
    return sass('css/main.scss')
    .on('error', function (err) {
      console.error('Error', err.message);
    })
    .pipe(gulp.dest('css/main.css'));
  });
  </code></pre>
  
  <p>But Everytime I type "gulp sass" the console prints:</p>
  
  <pre><code>Error Missing the SASS executable. Please install and make it available on your PATH.
  </code></pre>
  
  <p>I have included the directory of my ruby bin in the PATH var (system variables within Enviroment variables).</p>
  
  <p>I'm on Windows 8.1</p>
  
  <pre><code>ruby -v
  ruby 1.9.3p545 (2014-02-24) [i386-mingw32]
  
  node -v 
  v0.10.29
  
  npm -v
  1.4.14
  
  sass -v
  Sass 3.4.8 (Selective Steve)
  </code></pre>