title: How to pass environment variables to shinyapps
body: <p>I want to pass secure parameters to shinyapps.io deployment so my application could get them via:</p>
  
  <p><code>Sys.getenv('PASSWORD_X')</code></p>
  
  <p>I cannot find anything for this in <code>deployApp</code> function in the <code>rsconnect</code> package.</p>