Update crontab class to allow with context manager
with __enter__ and __exit__ methods added to the CronTab class you should be able to use the with context manager like so:
with CronTab(user=True) as cron:
job = cron.new(command="...", comment="...")
job.minute.every(1)
for item in cron:
print(item)
print("cron.write() called upon exit of the context")