title: Change the y limits ( especially the minimum) with Vlnplot
body: <p>I would like to draw a violin plot from my single cell data.</p>
  <p>I am using this function :</p>
  <pre><code>Vlnplot(object, features, cols = NULL, pt.size = 0.1)
  </code></pre>
  <p>But I would like to change the y axis to 3000-10000 instead of 0-70000.</p>
  <p>They only propose to change the y max but not the mean</p>
  <p>Does someone have an idea how to do it ?</p>