Add "conflict" declaration to composer.json

martin-helmich · martin-helmich · commit 71372ca107bc · 2019-03-22T18:52:31.000+01:00
diff --git a/composer.json b/composer.json
@@ -17,6 +17,9 @@
         "guzzlehttp/psr7": "^1.2",
         "phpunit/phpunit": "^8.0"
     },
+    "conflict": {
+        "phpunit/phpunit": "<8.0 || >= 9.0"
+    },
     "autoload": {
         "psr-4": {
             "Helmich\\Psr7Assert\\": "src/"
