title: How to write Git hash to (node's) package.json?
body: <p>is there a way to automatically update version number of a package.json (<a href="https://npmjs.org/doc/json.html">https://npmjs.org/doc/json.html</a>) with the HEAD hash of git? I would like to have something like <code>version: 1.0.0+rev82e4b91cfe42cd86e9453b4987b9cc446566de6</code> inside the project's package.json file. Eveything before the plus is set manually and the hash is updated everytime I commit something.</p>
  
  <p>Is this possible? I couldn't find anything on this topic :-/</p>