Allow use with both guzzle 4 and guzzle 5

composer.json

@@ -15,7 +15,7 @@
 		}
 	},
 	"require": {
-		"guzzlehttp/guzzle": "~5.0",
+		"guzzlehttp/guzzle": "~4.0|~5.0",
 		"symfony/console": "~2.3",
 		"symfony/process": "~2.3"
 	},

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at http://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "hash": "2e0d460d3256326008b6c2c37cce09d0",
+    "hash": "fd36b68ae6339bd08cc8baa6cc53b526",
     "packages": [
         {
             "name": "guzzlehttp/guzzle",