Merge pull request #336 from tighten/tm/bump-guzzlehttp-ps7

Bump the guzzlehttp/ps7 version

Author: tonysm

composer.json

@@ -20,7 +20,7 @@
         "ext-json": "*",
         "ext-pcntl": "*",
         "ext-posix": "*",
-        "guzzlehttp/psr7": "^1.7"
+        "guzzlehttp/psr7": "^2.6"
     },
     "require-dev": {
         "guzzlehttp/guzzle": "^7.4",