Update composer.json

Author: maurouberti

composer.json

@@ -29,7 +29,7 @@
     "predis/predis": "^1.1"
   },
   "require-dev": {
-    "laravel/lumen-framework": "~5.4",
+    "laravel/lumen-framework": "~6.0",
     "phpunit/phpunit": "^7.5",
     "phpunit/php-code-coverage": "^6.1",
     "php-coveralls/php-coveralls": "^2.1",