Merge pull request #840 from laravel/fix-commonmark

[2.x] Fix commonmark install issue

Author: driesvints

composer.json

@@ -18,7 +18,7 @@
         "ext-json": "*",
         "illuminate/support": "^8.0",
         "jenssegers/agent": "^2.6",
-        "league/commonmark": "^1.3",
+        "league/commonmark": "^1.3|^2.0",
         "laravel/fortify": "^1.6.1"
     },
     "require-dev": {