title: node-sass install script ignore .npmrc settings
body: <p>Try to install node-sass behind corporate proxy. I have configured nexus and set it in .npmrc</p>
  
  <pre><code>registry = http://dev/nexus/repository/npmjs_org/
  strict-ssl = false
  sass_binary_site = http://dev/nexus/repository/nodesass_downloads/
  </code></pre>
  
  <p>then I try to install packages</p>
  
  <pre><code>$ npm ci
  
  &gt; fsevents@1.2.7 install C:\***\ui\node_modules\fsevents
  &gt; node install
  
  
  &gt; fsevents@1.2.4 install C:\***\ui\node_modules\react-scripts\node_modules\fsevents
  &gt; node install
  
  
  &gt; node-sass@4.11.0 install C:\***\ui\node_modules\node-sass
  &gt; node scripts/install.js
  
  Downloading binary from https://github.com/sass/node-sass/releases/download/v4.11.0/win32-x64-57_binding.node
  Cannot download "https://github.com/sass/node-sass/releases/download/v4.11.0/win32-x64-57_binding.node":
  
  getaddrinfo ENOTFOUND github.com github.com:443
  
  Hint: If github.com is not accessible in your location
        try setting a proxy via HTTP_PROXY, e.g.
  
        export HTTP_PROXY=http://example.com:1234
  
  or configure npm proxy via
  
        npm config set proxy http://example.com:8080
  
  &gt; node-sass@4.11.0 postinstall C:\***\ui\node_modules\node-sass
  &gt; node scripts/build.js
  
  .......
  </code></pre>
  
  <p>As you can see <code>sass_binary_site</code> totally ignored. What is wrong?</p>