title: How to add URL handler for static html page in app.yaml running along Angular aplication
body: <p>I'm trying to setup a static html page that will be shown once user has unsubscribed from mailing list. This file should be in the same Google App Engine as my main Angular 7 app. But when visiting URL <code>https://MYURL/unsubscribe</code> I get 404 error. How do I need to configure my app.yaml in order to get this kind of functionality working?</p>
  
  <pre><code>runtime: python27
  api_version: 1
  threadsafe: true
  
  service: XXX
  
  handlers:
    # handler for static unsubscribe page
    - url: /unsubscribe\.html
      static_files: unsubscribe.html
      upload: unsubscribe.html
  
    - url: /
      secure: always
      static_files: dist/index.html
      upload: dist/.*
    - url: /(.*\.js)
      secure: always
      redirect_http_response_code: 301
      static_files: dist/\1
      upload: dist/.*\.js
    - url: /(.*\.css)
      secure: always
      redirect_http_response_code: 301
      static_files: dist/\1
      mime_type: text/css
      upload: dist/.*\.css
    - url: /.*
      secure: always
      static_files: dist/index.html
      upload: dist/.*
  
  skip_files:
    - ^(?!dist)
    - ^(?!unsubscribe.html)
  </code></pre>
  
  <p>I expect to see the content of my unsubscribe.html file when I go to <code>https://MYURL/unsubscribe</code>, but instead I get error saying <code>Error: Not Found
  The requested URL /unsubscribe.html was not found on this server.</code></p>
  
  <h1>UPDATE</h1>
  
  <p>Finally fixed it by combining last two line of my <code>app.yaml</code>file like so:</p>
  
  <pre><code>skip_files:
    - ^(?!dist|unsubscribe.html)
  </code></pre>
  
  <p>Now working as expected.</p>