Update and rename non_deleteable.py to non_deletable.py

Author: KateFinegan

python-del-statement/non_deleteable.py python-del-statement/non_deletable.pypython-del-statement/non_deleteable.py renamed to python-del-statement/non_deletable.py

@@ -1,4 +1,4 @@
-class NonDeleteable:
+class NonDeletable:
     def __init__(self, value):
         self.value = value