title: aws cli: update-kubeconfig not working as expected
body: <p>I am trying to update kubeconfig file using the below mentioned CLI</p>
  <pre><code>aws eks update-kubeconfig --name EKS_cluster
  </code></pre>
  <p>It is giving me this error</p>
  <pre><code>usage: aws [options] &lt;command&gt; &lt;subcommand&gt; [&lt;subcommand&gt; ...] [parameters]
  To see help text, you can run:
  
    aws help
    aws &lt;command&gt; help
    aws &lt;command&gt; &lt;subcommand&gt; help
  aws: error: argument operation: Invalid choice, valid choices are:
  
  create-cluster                           | delete-cluster
  describe-cluster                         | list-clusters
  help
  </code></pre>
  <p>The was cli version I am using is</p>
  <pre><code>aws-cli/1.15.58 Python/3.5.2 Linux/5.3.0-1030-aws botocore/1.10.57
  </code></pre>
  <p>Can someone help me with this?</p>