climada.test.test_calibration: fix import

Author: emanuel-schmid

climada/test/test_calibration.py

@@ -29,11 +29,14 @@
 from climada.engine.calibration_opt import calib_instance
 from climada.util.constants import ENT_DEMO_TODAY
 import climada.hazard.test as hazard_test
+from climada.test import get_test_file
+
 
 HAZ_TEST_MAT = get_test_file('atl_prob_no_name', file_format='matlab')
 
 DATA_FOLDER = CONFIG.test_data.dir()
 
+
 class TestCalib(unittest.TestCase):
     """Test engine calibration method."""