Update api_spec.md
Update api_spec.md

Adds the stop command
sterlingbaldwin/acme-web-fe,ACME-OUI/acme-web-fe,ACME-OUI/acme-web-fe,ACME-OUI/acme-web-fe,sterlingbaldwin/acme-web-fe,ACME-OUI/acme-web-fe,sterlingbaldwin/acme-web-fe,sterlingbaldwin/acme-web-fe