Update composer.json

Author: Nyholm

composer.json

@@ -4,7 +4,7 @@
     "license": "MIT",
     "require": {
         "php": "^7.1.3",
-        "psr/http-client": "^0.3.0",
+        "psr/http-client": "^1.0",
         "psr/http-factory": "^1.0",
         "symfony/config": "^4.1",
         "symfony/contracts": "dev-master",