Update composer.json

Author: Krzysztof Grzelak

composer.json

@@ -2,12 +2,12 @@
     "name": "simpaypl/simpay",
     "description": "Official SimPay API",
     "type": "library",
-    "version": "1.4",
+    "version": "1.5",
     "license": "MIT",
     "minimum-stability": "stable",
     "require": {
         "php": ">=7.0",
-    	"guzzlehttp/guzzle": "~6.0"
+    	"guzzlehttp/guzzle": "^6.0"
     },
     "authors": [
         {