title: Maven multi-project child can't have same version
body: <p>I have this maven multi-project configuration with a parent project and three child projects:</p>
  
  <p>Parent POM:</p>
  
  <pre><code>&lt;...&gt;
  &lt;groupId&gt;my.proj&lt;/groupId&gt;
  &lt;artifactId&gt;parent&lt;/artifactId&gt;
  &lt;packaging&gt;pom&lt;/packaging&gt;
  &lt;version&gt;1.0&lt;/version&gt;
  </code></pre>
  
  <p>Children POM:</p>
  
  <pre><code>&lt;parent&gt;
   &lt;groupId&gt;my.proj&lt;/groupId&gt;
   &lt;artifactId&gt;parent&lt;/artifactId&gt;
   &lt;version&gt;1.0&lt;/version&gt;
  &lt;/parent&gt;
  &lt;groupId&gt;my.proj.web&lt;/groupId&gt;
  &lt;artifactId&gt;web&lt;/artifactId&gt;
  &lt;version&gt;1.0&lt;/version&gt;
  </code></pre>
  
  <p>If I set the children version to 1.0, I get a warning:</p>
  
  <pre><code>version is duplicate of parent version
  </code></pre>
  
  <p>But that is what I want, because my entire project is version 1.0, it looks natural to me. Why is this not allowed (or discouraged)?</p>