Add test for forceRemake option

This also significantly improves the test coverage
as now the actual task will always run instead of it usually
just loading a pre-made image from the whatever the underlying
repo is.

tests/test_bestEffortIsr.py

@@ -43,9 +43,14 @@ def setUpClass(cls):
         cls.dataId = {'day_obs': 20210121, 'seq_num': 743, 'detector': 0}
 
     def test_getExposure(self):
+        # in most locations this will load a pre-made image
         exp = self.bestEffortIsr.getExposure(self.dataId)
         self.assertIsInstance(exp, afwImage.Exposure)
 
+        # this will always actually run isr with whatever calibs are available
+        exp = self.bestEffortIsr.getExposure(self.dataId, forceRemake=True)
+        self.assertIsInstance(exp, afwImage.Exposure)
+
 
 class TestMemory(lsst.utils.tests.MemoryTestCase):
     pass