title: Change region in new App Engine Flexible project
body: <p>I created a new App Engine Flexible Node.js project with a custom runtime (the dockerfile is just based on the node app engine image for now).
  The first time I deployed it I could select a region and had chosen for EU.
  But I now get this error because the flexible runtime is not yet available in Europe:</p>
  
  <blockquote>
    <p>ERROR: (gcloud.app.deploy) INVALID_ARGUMENT: Flexible Environment
    deployments are not supported in the apps region 'europe-west'.</p>
  </blockquote>
  
  <p>I'm now trying to change my region, but I have no idea where I can do that.
  I did gcloud init again and had chosen for us-west1.
  In ~/.config/gcloud/configurations/config_default I can see that the zone is 'us-west1-b' and the region is 'us-west1'.</p>
  
  <p>But after a new gcloud app deploy I get the same error.
  Where is the region stored? How can I change it without removing the project.</p>