title: Ignore duplicates when pushing nuget package to nuget.org from VSTS
body: <p>I got a build in VSTS that are triggered on every commit in the repository. Everything works great with one exception.</p>
  
  <p>We do not release a new version of the nuget package on every commit. So our nuget push build step fails with http status code 409. I've configured that step so that it can continue anyway.</p>
  
  <p>Due to the error the build is just "partially successful". I'm using the a build badge which also states the same (without context).</p>
  
  <p>How can I tell VSTS to ignore 409 or just replace the existing package (on nuget.org)?</p>