title: Change default timeout for mocha
body: <p>If we have a unit test file my-spec.js and running with mocha: </p>
  
  <pre><code>mocha my-spec.js
  </code></pre>
  
  <p>The default timeout will be 2000 ms. It can be overwritten for partial test with a command line parameter: </p>
  
  <pre><code>mocha my-spec.js --timeout 5000
  </code></pre>
  
  <p>Is it possible to change the default timeout globally for all tests? 
  i.e. the default timeout value will be different from 2000 ms when you call:</p>
  
  <pre><code>mocha my-spec.js
  </code></pre>