Update HARK_PRECISION import path in test

Changed the import of HARK_PRECISION from 'HARK.tests' to 'tests' in test_ConsHealthModel.py to reflect the correct module location.

Author: alanlujan91

tests/ConsumptionSaving/test_ConsHealthModel.py

@@ -1,5 +1,5 @@
 import unittest
-from HARK.tests import HARK_PRECISION
+from tests import HARK_PRECISION
 from HARK.ConsumptionSaving.ConsHealthModel import BasicHealthConsumerType