title: Using grunt to update base href
body: <p>During the build process of an angular app, I would like to update the <code>&lt;base href="/app-dev/"&gt;</code> tag to <code>&lt;base href="/app/"&gt;</code> inside <code>index.html</code></p>
  
  <p>Is there a way to update this tag with <code>usemin</code> (for now, I use it to update the links to the js and css)? If not, what grunt task should I use to do that? </p>