title: Use Composer without Packagist
body: <p>Say for instance you want to use a bundle from someone else, but want to do some modifications. So you do your modifications in some new branch, and configure comspoer.json like:</p>
  
  <pre><code>{
      "require": {
          "sylius/assortment-bundle": "dev-soft-deleteable-products-disabled"
      },
      "repositories": [
          {
              "type": "package",
              "package": {
                  "name": "sylius/assortment-bundle",
                  "version": "1.0",
                  "autoload": { "psr-0": { "Sylius\\Bundle\\AssortmentBundle": "" } },
                  "target-dir": "Sylius/Bundle/AssortmentBundle",
                  "source": {
                      "url": "https://github.com/umpirsky/SyliusAssortmentBundle.git",
                      "type": "git",
                      "reference": "soft-deleteable-products-disabled"
                  }
              }
          }
      ]
  }
  </code></pre>
  
  <p>This works with master branch, but with custom branch it gives: <code>The requested package sylius/assortment-bundle dev-soft-deleteable-products-disabled could not be found.</code></p>
  
  <p>Any idea?</p>