Allow error in slice to volume registration.
Allow error in slice to volume registration.

In the testing framework the slice to volume registration may fail
(too many samples outside moving image) because we use a much smaller
image due to memory constraints. Accomodate for these occasional
failures by allowing them.

zivy/SimpleITK-Notebooks,InsightSoftwareConsortium/SimpleITK-Notebooks,zivy/SimpleITK-Notebooks,InsightSoftwareConsortium/SimpleITK-Notebooks,InsightSoftwareConsortium/SimpleITK-Notebooks,zivy/SimpleITK-Notebooks