title: Cloud Datalab fails to launch
body: <p>Keep getting the following error when trying to launch Cloud Datalab. Tried deleting all listed VMs in the project, but still does not work.</p>
  
  <pre><code>Oct 27 10:50:31 datalab-deploy-main-20151027-10-41-31 startupscript: 10:50 AM Checking if updated app version is serving. 
  Oct 27 10:50:31 datalab-deploy-main-20151027-10-41-31 startupscript: 10:50 AM Not enough VMs ready (0/1 ready, 1 still deploying). Version: datalab:main.388142264345574525 
  Oct 27 10:50:31 datalab-deploy-main-20151027-10-41-31 startupscript: ERROR: Not enough VMs ready (0/1 ready, 1 still deploying). Version: datalab:main.388142264345574525 
  Oct 27 10:50:31 datalab-deploy-main-20151027-10-41-31 startupscript: 10:50 AM Rolling back the update. This can sometimes take a while since a VM version is being rolled back. 
  Oct 27 10:50:32 datalab-deploy-main-20151027-10-41-31 startupscript: Could not start serving the given version. 
  Oct 27 10:50:32 datalab-deploy-main-20151027-10-41-31 startupscript: ERROR: (gcloud.preview.app.deploy) Command failed with error code [1] 
  Oct 27 10:50:32 datalab-deploy-main-20151027-10-41-31 startupscript: Step deploy datalab module failed.
  </code></pre>