Mttl.py script delete option does not remove ksats in parent fields of Mttl files

Expected Behavior:

All references to deleted KSAT need to be removed.

Current Behavior:

Does not delete KSAT from parent list in file.

Possible Solution:

Steps to Reproduce:

• Run ./mttl.py delete ksat [KSAT ID] for a KSAT that that has children
• Review edited file and view one of the child KSATs to see deleted KSAT is still listed as parent