title: Composer conflicts and Symfony 3
body: <p>I'm totally new to composer and symfony, and i've started a symfony3 project. Things where going well, but now composer won't update my dependancies. I've been searching a solution for 3 hours. </p>
  
  <p>Here is my console log:</p>
  
  <pre><code>  Problem 1
  - sonata-project/admin-bundle dev-master requires sonata-project/block-bundle 3.x-dev@dev -&gt; satisfiable by sonata-project/block-bundle[3.x-dev] but these conflict with your requirements or minimum-stability.
  - sonata-project/admin-bundle dev-master requires sonata-project/block-bundle 3.x-dev@dev -&gt; satisfiable by sonata-project/block-bundle[3.x-dev] but these conflict with your requirements or minimum-stability.
  - Installation request for sonata-project/admin-bundle dev-master -&gt; satisfiable by sonata-project/admin-bundle[dev-master].
  </code></pre>
  
  <p>And my composer.json requirements: </p>
  
  <pre><code>    "require": {
      "php": "&gt;=5.5.9",
      "symfony/symfony": "3.0.*",
      "doctrine/orm": "^2.5",
      "doctrine/doctrine-bundle": "^1.6",
      "doctrine/doctrine-cache-bundle": "^1.2",
      "symfony/swiftmailer-bundle": "^2.3",
      "symfony/monolog-bundle": "^2.8",
      "sensio/distribution-bundle": "^5.0",
      "sensio/framework-extra-bundle": "^3.0.2",
      "incenteev/composer-parameter-handler": "^2.0",
      "friendsofsymfony/user-bundle": "dev-master",
      "sonata-project/admin-bundle": "dev-master",
      "sonata-project/doctrine-orm-admin-bundle": "dev-master"
  },
  </code></pre>
  
  <p>If you can find the problem, and explain it to me, you're going to be my hero!</p>