Broader guzzle/parser version req

Author: cboden

composer.json

@@ -5,7 +5,7 @@
     "license": "MIT",
     "require": {
         "php": ">=5.3.3",
-        "guzzle/parser": "~3.0",
+        "guzzle/parser": "~2.8|~3.0",
         "react/socket": "0.3.*"
     },
     "autoload": {