update dependencies

Author: ngabor84

composer.json

@@ -14,13 +14,13 @@
         }
     ],
     "require": {
-    	"php": "~7.1",
-        "laravel/lumen-framework": "~5.4"
+    	"php": "~7.2",
+        "laravel/lumen-framework": "~6.0"
     },
     "require-dev": {
-        "mockery/mockery": "~0.9",
-        "phpunit/phpunit": "~6.1",
-        "squizlabs/php_codesniffer": "3.0.0RC4"
+        "mockery/mockery": "~1.2",
+        "phpunit/phpunit": "~8.3",
+        "squizlabs/php_codesniffer": "~3.4"
     },
     "autoload": {
         "psr-4": {
@@ -42,4 +42,4 @@
 	},
     "minimum-stability": "stable",
     "prefer-stable": true
-}
+}