Bump monolog version

composer.json

@@ -18,7 +18,7 @@
     "require": {
         "php": ">=5.3.2",
         "doctrine/common": "2.1.*",
-        "monolog/monolog": "1.0.*",
+        "monolog/monolog": ">=1.0,<1.2-dev",
         "swiftmailer/swiftmailer": ">=4.1.2,<4.2-dev",
         "twig/twig": ">=1.1,<2.0-dev"
     },