test: fixed wrong import

Author: MarkusPic

tests/test_idf_backend.py

@@ -2,7 +2,7 @@
 
 import pytest
 import numpy as np
-from idf_analysis.idf_backend import IdfParameters
+from idf_analysis.idf_backend_2012 import IdfParameters
 from idf_analysis.definitions import SERIES, METHOD, PARAM, APPROACH
 from idf_analysis.parameter_formulas import HyperbolicAuto, DoubleLogNormAuto, LinearFormula