Dockerize App

[alfiyansys]

Is your feature request related to a problem? Please describe.
It's sometimes just can't build on legacy systems, e.g. Ubuntu 16.04, because of lack of newest golang support

Describe the solution you'd like
Dockerize the app, its can be run as simply :
docker run subping <args>

Describe alternatives you've considered
No alternatives

[fadhilyori]

Thank you, this will be useful also for automation. Added to milestone v1.1.0