title: Setting Windows env vars via azure-pipelines.yml + script
body: <p>Following Azure <a href="https://docs.microsoft.com/en-us/azure/devops/pipelines/yaml-schema?view=azure-devops&amp;tabs=schema#script" rel="nofollow noreferrer">script</a> yaml documentation the <code>script</code> stanza (not sure of YAML terminology sorry) should be able to set environment variables.</p>
  
  <p>I am finding adding a Windows job, my Python code is not seeing the environment variable. Is this <a href="https://github.com/facebookincubator/ptr/pull/32/files" rel="nofollow noreferrer">PR</a> doing it correctly? Full azure-pipeliens.yml can be found <a href="https://github.com/facebookincubator/ptr/blob/master/azure-pipelines.yml" rel="nofollow noreferrer">here</a></p>
  
  <ul>
  <li>Also now my MacOS job has stopped running the <code>ci.py</code></li>
  </ul>
  
  <p>I suspect I'm doing something wrong, <em>any</em> pointers would be great. Thanks.</p>