Update orchestra/testbench requirement from ~5.1.0 to ~5.1.0 || ~5.3.0 (#6)

Author: dependabot-preview[bot]

composer.json

@@ -30,7 +30,7 @@
         }
     },
     "require-dev": {
-        "orchestra/testbench": "~5.1.0",
+        "orchestra/testbench": "~5.1.0 || ~5.3.0",
         "phpunit/phpunit": "~8.5"
     },
     "autoload-dev": {