minor #852 Use a proper version constraint (GrahamCampbell)

This PR was merged into the 2.8 branch.

Discussion
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Use a proper version constraint

Any reason why this wasn't used already? I noticed this when looking at #850.

Commits
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8d04960 Use a proper version constraint

Author: Tobion

composer.json

@@ -9,7 +9,7 @@
     },
     "require": {
         "php": ">=5.3.9",
-        "symfony/symfony": "2.8.x-dev",
+        "symfony/symfony": "2.8.*@dev",
         "doctrine/orm": "^2.4.8",
         "doctrine/doctrine-bundle": "~1.4",
         "symfony/swiftmailer-bundle": "~2.3",