Use Github actions to push docker image to hub

[r0mdau]

Maybe will fix #11 . It is working well in my repo.

@phocean you need to :

1. create a Token in your hub.docker.com account
2. in this project settings add 2 secrets :
3. DOCKER_HUB_USERNAME: phocean
4. DOCKER_HUB_ACCESS_TOKEN: your token
5. Merge this :smiley: