This was added to fetch the ansible errors via mistral api. We had
long removed the json_error.py callback plugin that used to write
ansible-errors.json, when moving ansible code to tripleo-ansible
repo and the command is useless now. Also, users won't need it as
they can get the errors from ansible.log.
Change-Id: Iceb4c282f3ae9fcb2c3836263ba66f5792e42334
7cef22cc68