title: webpack/encore from symfony 4 with socket.io
body: <p>I tried to use socket.io in my symfony 4 project, still I encounter some issues.
  I used <strong>npm install --save socket.io</strong></p>
  
  <p>then i get this : </p>
  
  <pre><code>npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules\fsevents):
  npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"win32","arch":"x64"})
  
  + socket.io@2.1.1
  added 101 packages in 9.519s
  </code></pre>
  
  <p>But i was thinking "it's ok, it just notice me and it look optionnal".</p>
  
  <p>Still when i used <strong>webpack/encore</strong> i get : </p>
  
  <pre><code>PS C:\wamp64\www\PROJETS\my-projet&gt; ./node_modules/.bin/encore dev
  Running webpack ...
  
   ERROR  Failed to compile with 2 errors                                                                         15:41:22
  
  These dependencies were not found:
  
  * fs in ./node_modules/socket.io/lib/index.js
  * uws in ./node_modules/engine.io/lib/server.js
  
  To install them, you can run: npm install --save fs uws
  </code></pre>
  
  <p>But install what they want (<strong>fs uws</strong>) don't make it work better when i use <strong>webpack/encore</strong>...
  What should i do ?</p>