title: Travis and matrix combinations
body: <p>I want to test different builds of my .js framework against many browsers</p>
  
  <p>I expected to write something like:</p>
  
  <pre><code>language: node_js
  node_js:
  - 0.11
  env:
    matrix:
      - BUILD='nocompat'
      - BUILD='compat'
      - BUILD='default'
  
      - BROWSER='ie6'
      - BROWSER='ie7'
      # etc... about total 15 browsers/platforms
  </code></pre>
  
  <p>But the only way I got it working was specifying all combinations "by hand"...</p>
  
  <p>Like:</p>
  
  <pre><code>env:
    matrix:
      - BROWSER='chrome_linux'    BUILD='default'
      - BROWSER='chrome_linux'    BUILD='compat'
      - BROWSER='chrome_linux'    BUILD='nocompat'
      - BROWSER='firefox'         BUILD='default'
      - BROWSER='firefox'         BUILD='compat'
      - BROWSER='firefox'         BUILD='nocompat'
  
      # etc ... and this is about 50 lines!
  </code></pre>
  
  <p>Is there another way to do this? Or is this the right way?</p>