minor #769 Update the lowest bound of the Twig dev requirement (Timot…

…hée)

This PR was squashed before being merged into the 1.4-dev branch (closes #769).

Discussion
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Update the lowest bound of the Twig dev requirement

I fix it a Twig depreciation, see twigphp/Twig@e3a325f for more information.

Thanks

Commits
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b887ab7 Update the lowest bound of the Twig dev requirement

composer.json

@@ -22,7 +22,7 @@
     "require-dev": {
         "phpunit/phpunit": "~4.8",
         "symfony/phpunit-bridge": "~2.7|~3.0",
-        "twig/twig": "~1.8|~2.0",
+        "twig/twig": "~1.23|~2.0",
         "leafo/lessphp": "^0.3.7",
         "leafo/scssphp": "~0.1",
         "ptachoire/cssembed": "~1.0",