title: Add Helm chart dependency repository as git url
body: <p>I create a Helm chart that depends on several sub charts. I add the sub charts in the file <code>Chart.yaml</code>, this works well for charts from the stable repository.</p>
  <p>But I also want to add dependencies on other charts. Currently I use <code>Helm install https://github.com/.../releases/my-chart.tgz</code> to install charts, which does not work in the <code>Chart.yaml</code> file at the moment. Is there a way to use this in the dependency field in the <code>Chart.yaml</code> file?</p>
  <p>Is there also a way to use a git repository <code>https://github.com/my-chart/</code> as a reference to install a chart as a dependency?</p>
  <p>Or is it really only possible to use chart repositories or locale chart directorys?</p>
  <p>Thanks</p>