title: Remove environment variables from a deployment when they are no longer listed in a template's deployment config
body: <p>OpenShift (and probably k8s, too) updates a deployment's existing environment variables and creates new ones when they were changed in the respective <code>DeploymentConfig</code> in a template file before applying it.</p>
  
  <p>Is there a way to remove already existing environment variables if they are no longer specified in a template when you run <code>oc apply</code>?</p>