Updated PhpUnit to version 9, and moved http-factory to dev-dependency

Author: Logifire

.gitignore

@@ -1 +1,2 @@
 /vendor/
+.phpunit.result.cache

composer.json

@@ -5,8 +5,7 @@
     "require": {
         "php": "^7.4",
         "psr/http-server-middleware": "^1.0",
-        "psr/http-server-handler": "^1.0",
-        "psr/http-factory": "^1.0.0"
+        "psr/http-server-handler": "^1.0"
     },
     "autoload": {
         "psr-4": {
@@ -19,8 +18,9 @@
         }
     },
     "require-dev": {
-        "phpunit/phpunit": "7.5.1",
-        "nyholm/psr7": "1.0.1"
+        "phpunit/phpunit": "^9.5.9",
+        "nyholm/psr7": "^1.0.1",
+        "psr/http-factory": "^1.0.0"
     },
     "provide": {
         "psr/http-server-handler-implementation": "1.0"