invalid_arguments response when deleting messages

[sgratzl]

Problem:

Channel messages are not being deleted when the script is performed. Results in invalid_arguments error.

example:

Failed to delete (invalid_arguments)->
{   'client_msg_id': 'XXX',
    'team': 'XXX',
    'text': 'XXX',
    'ts': '1541698411.011700',
    'type': 'message',
    'user': 'XXX'
}

Solution:

Slack chat.delete usually requires argument as_user=True

so add the command line argument: --as_user

--as_user            Pass true to delete the message as the authed user. Bot
                       users in this context are considered authed users.