minor #33 Allow the PHPUnit bridge v4 (dunglas)

This PR was merged into the 3.0-dev branch.

Discussion
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Allow the PHPUnit bridge v4

Follows 3bf313c. ping @nicolas-grekas

Commits
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64812c6 Allow the PHPUnit bridge v4

Author: fabpot

composer.json

@@ -20,7 +20,7 @@
         "symfony/security-core": "~2.8|~3.0|~4.0"
     },
     "require-dev": {
-        "symfony/phpunit-bridge": "~2.8|~3.0",
+        "symfony/phpunit-bridge": "~2.8|~3.0|~4.0",
         "doctrine/common": "~2.2",
         "doctrine/dbal": "~2.2",
         "psr/log": "~1.0"