sysutils/py-mitogen: new port

[dch]

Summary

Ansible accelerator and Python library for writing distributed programs

Test Plan

• portlint -AC ok
• actually works with real ansible (python 3.6 flavour tested)
• poudriere matrix ok (11.2R, 12.0R i686+amd64, 12.0R aarch64 & 13.0-CURRENT amd64) and both flavours

[dch]

s/it's/its/

[jrm]

[matthew]

[bcr]

Thanks for working on it!