title: Checkout repository based on Tag in the Jenkins Workflow plugin
body: <p>With the <a href="https://github.com/jenkinsci/workflow-plugin" rel="noreferrer">Jenkins Workflow Plugin</a>, I can checkout a repository based on branch. However, I would like to checkout a repository based on a tag.</p>
  
  <p>This is my current configuration for checking out the master branch</p>
  
  <pre><code>node {
      git url: src, branch: 'master'
  }
  </code></pre>
  
  <p>Now I would like to achieve to check out tag 3.6.1. I tried to change the branch to a tag, but that won't work. Neither is there something in the documentation regarding checking out on tag.</p>
  
  <p>Is this currently possible? Am I overseeing something?</p>
  
  <p>references;</p>
  
  <p><a href="https://github.com/jenkinsci/workflow-plugin" rel="noreferrer">https://github.com/jenkinsci/workflow-plugin</a></p>
  
  <p><a href="https://github.com/jenkinsci/workflow-plugin/blob/master/scm-step/README.md" rel="noreferrer">https://github.com/jenkinsci/workflow-plugin/blob/master/scm-step/README.md</a></p>
  
  <p><a href="https://github.com/jenkinsci/workflow-plugin/blob/master/scm-step/src/main/resources/org/jenkinsci/plugins/workflow/steps/scm/GitStep/config.jelly" rel="noreferrer">https://github.com/jenkinsci/workflow-plugin/blob/master/scm-step/src/main/resources/org/jenkinsci/plugins/workflow/steps/scm/GitStep/config.jelly</a></p>
  
  <p><a href="https://github.com/jenkinsci/workflow-plugin/blob/master/scm-step/src/main/java/org/jenkinsci/plugins/workflow/steps/scm/GitStep.java" rel="noreferrer">https://github.com/jenkinsci/workflow-plugin/blob/master/scm-step/src/main/java/org/jenkinsci/plugins/workflow/steps/scm/GitStep.java</a></p>