add a schema with nullable

Author: JaredCE

test/schemas/nullProperties/nullAndType.json

@@ -0,0 +1,11 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "title": "JSON API Schema",
+  "description": "This is a schema for responses in the JSON API format. For more, see http://jsonapi.org",
+  "type": "object",
+  "properties": {
+    "typedProperty": {
+      "type": ["null", "string"]
+    }
+  }
+}