VED-457: refactor e-tag headers data type

Author: Akol125

e2e/test_create_immunization.py

@@ -40,7 +40,7 @@ def test_non_unique_identifier(self):
         # Check that duplice CREATE request is rejected after the event is updated
         imms["id"] = imms_id  # Imms fhir resource should include the id for update
         etag_version = int(res.headers["E-Tag"])
-        self.default_imms_api.update_immunization(imms_id, imms, headers={"E-Tag": etag_version})
+        self.default_imms_api.update_immunization(imms_id, imms, headers={"E-Tag": str(etag_version)})
         self.assertEqual(res.status_code, 200)
         del imms["id"]  # Imms fhir resource should not include an id for create
         self.assert_operation_outcome(self.default_imms_api.create_immunization(imms, expected_status_code=422), 422)