title: LARAVEL- how do I install a package that requires a previous version?
body: <p>I was looking to install this package - <strong><a href="https://github.com/faustbrian/Laravel-Invoice" rel="nofollow noreferrer">https://github.com/faustbrian/Laravel-Invoice</a></strong>  and when doing composer require faustbrian/laravel-invoice  I received an error stating: </p>
  
  <p><em>Installation request for faustbrian/laravel-invoice ^1.1 -> satisfiable by faustbrian/laravel-invoice[1.1.0].
      - Conclusion: remove laravel/framework v5.6.15
      - Conclusion: don't install laravel/framework v5.6.15
      - faustbrian/laravel-invoice 1.1.0 requires illuminate/support 5.4.</em> || 5.5.* -> satisfiable by illuminate/support[5.4.x-dev, 5.5.x-dev, v5.4.0, v5.4.13, v5.4.17, v5.4.19, v5.4.27, v5.4.36, v5.4.9, v5.5.0, v5.5.16, v5.5.17, v5.5.2, v5.5.28, v5.5.33, v5.5.34, v5.5.35, v5.5.36, v5.5.37, v5.5.39, v5.5.40].
      - illuminate/support 5.4.x-dev conflicts with laravel/framework[v5.6.15].*</p>
  
  <p>Is there a way to install this package without using an older version of Laravel (in this case 5.4)?</p>