Merge pull request #480 from wouterj/patch-1

Allow guzzlehttp/psr7 2.0

Author: manted

composer.json

@@ -6,7 +6,7 @@
   "require": {
     "php": ">=5.5.0",
     "guzzlehttp/guzzle": "^6.0 || ^7.0",
-    "guzzlehttp/psr7": "^1.7",
+    "guzzlehttp/psr7": "^1.7 || ^2.0",
     "mmucklo/inflect": "0.3.*"
   },
   "require-dev": {