Update dev require

Signed-off-by: Jack Cherng <[email protected]>

Author: jfcherng

composer.json

@@ -32,8 +32,8 @@
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^2.16",
-        "phan/phan": "^2.0",
-        "phpunit/phpunit": "^7.5 || ^8.0",
+        "phan/phan": "^2.4",
+        "phpunit/phpunit": "^7.5 || ^8 || ^9",
         "squizlabs/php_codesniffer": "^3.5"
     },
     "config": {