title: Yarn ignores proxy settings
body: <p>I try to get a build job running using yarn and react-native on a windows 10 machine. The following commands are executed inside of jenkins to prepare the actual build of a native Windows app.</p>
  
  <pre><code>yarn config set proxy http://192.109.190.88:8080 
  yarn config set https-proxy http://192.109.190.88:8080 
  yarn add react-native 
  </code></pre>
  
  <p>This leads to the following output although the proxy settings are correct (tried "<a href="http://192.109.190.88:8080/" rel="noreferrer">http://192.109.190.88:8080/</a>" as well):</p>
  
  <pre><code>yarn add v0.27.5
  [1/4] Resolving packages...
  warning There appears to be trouble with your network connection. Retrying...
  warning There appears to be trouble with your network connection. Retrying...
  warning There appears to be trouble with your network connection. Retrying...
  warning There appears to be trouble with your network connection. Retrying...
  </code></pre>
  
  <p>Any ideas on why this happens are well appreciated.</p>