minor #326 Added sf4 to composer. (mmaarriiuuss)

This PR was merged into the 3.2-dev branch.

Discussion
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Added sf4 to composer.

#SymfonyConHackday2017
Updated composer with Sf4. Tests should pass after #325 is accepted

Commits
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c724926 Added sf4 to composer.

composer.json

@@ -13,9 +13,9 @@
     ],
     "require": {
         "php": ">=5.5.0",
-        "symfony/browser-kit": "~2.1|~3.0",
-        "symfony/css-selector": "~2.1|~3.0",
-        "symfony/dom-crawler": "~2.1|~3.0",
+        "symfony/browser-kit": "~2.1|~3.0|~4.0",
+        "symfony/css-selector": "~2.1|~3.0|~4.0",
+        "symfony/dom-crawler": "~2.1|~3.0|~4.0",
         "guzzlehttp/guzzle": "^6.0"
     },
     "require-dev": {