title: Updating file references in a json file via a grunt task
body: <p>I'm a JavaScript developer and fairly new to creating a build process from scratch. I chose to use Grunt for my current project and have created a GruntFile that does about 90% of what I need it to do and it works great, except for this one issue. I have several JavaScript files that I reference while I'm developing a chrome extension in the <code>manifest.json</code> file. For my build process I am concatenating all of these files and minifying it into one file to be included in <code>manifest.json</code>. Is there anyway to update the file references in the <code>manifest.json</code> file during the build process so it points to the minified version?</p>
  
  <p>Here is a snippet of the src manifest file:</p>
  
  <pre><code>{
      "content_scripts": [{
          "matches": [
              "http://*/*"
          ],
          "js": [
              "js/lib/zepto.js",
              "js/injection.js",
              "js/plugins/plugin1.js",
              "js/plugins/plugin2.js",
              "js/plugins/plugin3.js",
              "js/injection-init.js"
          ]
      }],
      "version": "2.0",
  }
  </code></pre>
  
  <p>I have a grunt task that concatenates and minifies all the js files listed above into one file called <code>injection.js</code> and would like a grunt task that can modify the manifest file so it looks like this:</p>
  
  <pre><code>{
      "content_scripts": [{
          "matches": [
              "http://*/*"
          ],
          "js": [
              "js/injection.js"
          ]
      }],
      "version": "2.0",
  }
  </code></pre>
  
  <p>What I've done for now is have 2 versions of the manifest file, one for dev and one for build, during the build process it copies the build version instead. This means I need to maintain 2 versions which I'd rather not do. Is there anyway to do this more elegantly with Grunt?</p>