CLEANUP
added tests of modifyTasks() while I learn  to DELETE a task.

As it turns out the approach in updateTasks.gs wiped out all my SS data.
So will need to get a better way. But the tests will still be valid.
this updateTasks() DID NOT WORK

save but change. usinga copy and .slice wiped out all my data.
change to pop from orig array to modify, push to new array is safer.