title: Running "npm run build" with specific env file
body: <p>Whenever I run &quot;npm run build&quot; command, my vue project automatically use &quot;.env.production&quot; file(which is one of my .env files). I would like to build my project by specifying env files for example</p>
  <ol>
  <li>npm run build .env.production (to deploy on production server)</li>
  <li>npm run build .env.development (to deploy on development server)</li>
  </ol>
  <p>Is there any way I can specify environment variables when running &quot;npm run build&quot;????</p>