title: How to make dropdown for groups instead of checkboxes in Odoo?
body: <p>I have made some groups <code>A</code>,<code>B</code>,<code>C</code>,<code>D</code> through GUI in Odoo v10. These groups are shown as check-boxes on the user page. </p>
  
  <p>I want that instead of these check-boxes a dropdown must be shown so that user can be assigned to only a single group i.e. a user can only be in one of the <code>A</code>,<code>B</code>,<code>C</code>,<code>D</code> groups.</p>
  
  <p>How can i do this??</p>