Tweak package requirements

Author: sebastiaanluca

composer.json

@@ -24,14 +24,14 @@
         }
     ],
     "require": {
+        "php": "^7.2",
         "laravel/framework": "~5.8.0",
-        "nesbot/carbon": "^1.22.1|^2.0",
-        "php": "^7.2"
+        "nesbot/carbon": "^1.22.1|^2.0"
     },
     "require-dev": {
         "kint-php/kint": "^3.1",
         "mockery/mockery": "^1.2",
-        "orchestra/testbench": "^3.8",
+        "orchestra/testbench": "~3.8.0",
         "phpunit/phpunit": "^8.0"
     },
     "autoload": {