title: Force ignore one dependency's dependency from being installed by npm/yarn
body: <p>My nodejs project uses some libraries. One library <a href="https://www.npmjs.com/package/pouchdb" rel="noreferrer"><code>pouchdb</code></a> will try to install quite a lot of dependencies. There is one called <a href="https://www.npmjs.com/package/leveldown" rel="noreferrer"><code>leveldown</code></a>, which will try to download Node.js header from Internet and then rebuild everything from scratch. Actually I don't need the <code>leveldown</code> at all. But their community suggest me to privately fork a <code>pouchdb</code> and the modify the package.json to exclude any dependency I don't need.</p>
  
  <p>Here is my general question to npm/yarn folks. Is it possible to prevent particular library from being downloaded, while running <code>npm install</code> or <code>yarn install</code>?</p>