title: @Version is not being incremented in Spring mongo
body: <p>I have added 
  @Enableauditng as an annotation but @version is not incrementing the version on its own.
  I have @LastModifiedDate, which is being updated but not the @version.</p>
  
  <p>Am i doing somehting wrong.</p>
  
  <p>I am calling mongoTemplate.save(object) to againg and again.</p>
  
  <p>Please advice </p>