title: Error pushing docker hub using spotify/dockerfile-maven-plugin
body: <p>I have a maven project that is built as a docker image. I'm using <a href="https://github.com/spotify/dockerfile-maven" rel="noreferrer">spotify/dockerfile-maven</a> to build this image and push it to docker.hub automatically on on <code>mvn clean install</code>.
  The <code>build</code> phase passes without any problems. But on <code>push</code> I have this error:</p>
  
  <pre><code>[ERROR] denied: requested access to the resource is denied
  [WARNING] An attempt failed, will retry 1 more times
  org.apache.maven.plugin.MojoExecutionException: Could not push image
      at com.spotify.plugin.dockerfile.PushMojo.execute(PushMojo.java:90)
  ........
  Caused by: com.spotify.docker.client.exceptions.DockerException: denied: requested access to the resource is denied
      at com.spotify.plugin.dockerfile.LoggingProgressHandler.handleError(LoggingProgressHandler.java:105)
      at com.spotify.plugin.dockerfile.LoggingProgressHandler.progress(LoggingProgressHandler.java:63)
  ......
  </code></pre>
  
  <p>Here is my plugin config:</p>
  
  <pre><code>     &lt;build&gt;
          &lt;pluginManagement&gt;
              &lt;plugins&gt;
                  &lt;plugin&gt;
                      &lt;groupId&gt;com.spotify&lt;/groupId&gt;
                      &lt;artifactId&gt;dockerfile-maven-plugin&lt;/artifactId&gt;
                      &lt;version&gt;1.3.6&lt;/version&gt;
                      &lt;configuration&gt;
                          &lt;repository&gt;${docker.image.prefix}/${project.artifactId}-istio&lt;/repository&gt;
                          &lt;tag&gt;latest&lt;/tag&gt;
                      &lt;/configuration&gt;
                      &lt;executions&gt;
                          &lt;execution&gt;
                              &lt;phase&gt;package&lt;/phase&gt;
                              &lt;goals&gt;
                                  &lt;goal&gt;build&lt;/goal&gt;
                                  &lt;goal&gt;push&lt;/goal&gt;
                              &lt;/goals&gt;
                          &lt;/execution&gt;
                      &lt;/executions&gt;
                  &lt;/plugin&gt;
              &lt;/plugins&gt;
          &lt;/pluginManagement&gt;
      &lt;/build&gt;
  </code></pre>
  
  <p>When pushing with <code>docker push image-name:tag</code> everything works.</p>
  
  <p><a href="https://github.com/spotify/dockerfile-maven/issues/79#issuecomment-338563667" rel="noreferrer">Here</a> I have found the similar issue, but adding the dependency for <code>docker-client v8.8.4</code> does not change anything.</p>
  
  <p>Also, <a href="https://github.com/spotify/dockerfile-maven/issues/51#issuecomment-321549038" rel="noreferrer">this</a> comment suggest switching to <code>1.3.3</code> version, but this doesn't work for me.</p>
  
  <p>For both cases, I can see in the logs that it pushes to the same repository:</p>
  
  <pre><code>The push refers to a repository [docker.io/my-login/my-image-name]
  </code></pre>