Upgraded to commonmark 0.9

Author: Graham Campbell

composer.json

@@ -14,7 +14,7 @@
         "illuminate/contracts": "5.0.*|5.1.*",
         "illuminate/support": "5.0.*|5.1.*",
         "illuminate/view": "5.0.*|5.1.*",
-        "league/commonmark": "0.8.*"
+        "league/commonmark": "0.9.*"
     },
     "require-dev": {
         "graham-campbell/testbench": "~2.1"