remove sales value from forecast response

tests/analysis/test_forecast.py

@@ -225,8 +225,18 @@ def test_postprocess_sales_FailValidation(
     assert "ValidationError" in pipe.status.description
 
 
+def test_export_on_fail():
+    status = STATUS_HANDLER.pipe_states.TOO_FEW_POINTS
+    res = fc._export_on_fail(status)
+    assert res.response is not None
+    assert len(res.response.daten) == 0
+    assert res.status is not None
+    assert res.status.code == status.code
+    assert res.status.description == status.description
+
+
 def test_pipeline_sales_prognosis(exmpl_api_sales_prognosis_resp):
-    def mock_request(*args, **kwargs):
+    def mock_request(*args, **kwargs):  # pragma: no cover
         return exmpl_api_sales_prognosis_resp, STATUS_HANDLER.SUCCESS
 
     with patch(