Added ext-json as a requirement.

FabianBeiner · FabianBeiner · commit 730af66d078f · 2019-07-19T17:48:07.000+02:00
diff --git a/composer.json b/composer.json
@@ -36,7 +36,8 @@
   },
   "require": {
     "guzzlehttp/guzzle": "~6.3",
-    "php": ">=7.0"
+    "php": ">=7.0",
+    "ext-json": "*"
   },
   "require-dev": {
     "phpunit/phpunit": "^7.2"
