Update composer dependencies

Author: codenix-sv

composer.json

@@ -18,12 +18,11 @@
   ],
   "require": {
     "php": "^7.2",
-    "ext-json": "*"
-
+    "ext-json": "*",
+    "guzzlehttp/guzzle": "~6.0"
   },
   "require-dev": {
-    "phpunit/phpunit": "^8.0",
-    "guzzlehttp/guzzle": "~6.0"
+    "phpunit/phpunit": "^8.0"
   },
   "autoload": {
     "psr-4": { "Codenixsv\\BitfinexApi\\": "src/" }