[issue29958] Use add_mutually_exclusive_group(required=True) in zipfile and tarfile CLI

[Serhiy Storchaka]

Changes by Serhiy Storchaka <storchaka+cpython at gmail.com>:


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resolution:  -> fixed
stage: patch review -> resolved
status: open -> closed

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue29958>
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