Resolve "Implement an endpoint on DMS to send a command to a vm instance"

Checklist

• I have update updated the @version string in main.go. See https://semver.org/
• I have update CHANGELOG.md with a short description of changes.
• I have run swag init to update the swagger docs.

Description

• Added a ping-pong websocket server. Created stub for further work.
• The server assumes that every input coming is a command to be executed.