title: @CreatedBy and @LastModifiedDate are no longer working with ZonedDateTime?
body: <p>i have updated an old spring boot 1.5.3 project to spring boot 2.0.0. RELEASE. 
  I have an auditing entity with two fields of type ZonedDateTime annotated with @CreatedBy and @LastModifiedDate. </p>
  
  <p>In the previous versions everything was working fine. However,  with the new update, upon saving the entity in the repository i get an error i.e </p>
  
  <pre><code> createdDate=&lt;null&gt;
   lastModifiedDate=&lt;null&gt;
   ]! Supported types are [org.joda.time.DateTime, org.joda.time.LocalDateTime, java.util.Date, java.lang.Long, long]
  </code></pre>
  
  <p>I checked the <a href="https://github.com/spring-projects/spring-data-commons/blob/master/src/main/java/org/springframework/data/auditing/AnnotationAuditingMetadata.java" rel="noreferrer">AnnotationAuditingMetaData</a>, and i found noting related to ZonedDateTime. </p>
  
  <p>There is also this issue in <a href="https://jira.spring.io/browse/DATAJPA-1242" rel="noreferrer">https://jira.spring.io/browse/DATAJPA-1242</a>, I believe it's related. </p>
  
  <p>My question is what am i doing wrong here, does spring stopped the support or am i doing something wrong?</p>