Add test for Item model

cookiecutter/app/default/{{cookiecutter.app}}/{{cookiecutter.app}}/services/items/tests/fixtures/item.json

@@ -0,0 +1,4 @@
+{
+    "name": "test"
+}
+

cookiecutter/app/default/{{cookiecutter.app}}/{{cookiecutter.app}}/services/items/tests/test_items.py

@@ -0,0 +1,16 @@
+import pytest
+import json
+from pydantic import ValidationError
+from {{cookiecutter.app}}.services.items.model import Items
+
+def test_create_item():
+    with open("fixtures/item.json") as item_json_file:
+        item_json = json.load(item_json_file)
+        try:
+            item = Items(**item_json)
+        except ValidationError as error:
+            err_str = ""
+            for err_obj in error.errors():
+                err_str += "{} gave error {}\r\n".format(err_obj["loc"][0], err_obj["msg"])
+            pytest.fail(err_str)
+