title: PostCSS Autoprefixer not working with command line
body: <p>Right now, I'm currently working in a project in which i have to support flexbox for ie10, I'm trying to autoprefix some of my CSS code independently via terminal.</p>
  
  <p>The project does not support any build tool like gulp or webpack.</p>
  
  <p>So i have installed postcss and autoprefixer as follows:</p>
  
  <pre><code>npm install -g postcss autoprefixer
  </code></pre>
  
  <p>and then i'm trying to autoprefix a single file like so:</p>
  
  <pre><code>npx postcss --use autoprefixer --autoprefixer.flexbox --autoprefix.browser "&gt; 0%" -o main.css test.css
  </code></pre>
  
  <p>It works for most of my code, but it does not include any prefix for flexbox in ie10.</p>
  
  <p>Am i doing something wrong?</p>