Update Dockerfile to Ubuntu 20.04

[termdew]

Update Dockerfile:

• upgrade Ubuntu to 20.04
• add entry point to run server automatically from the docker container with "docker run --publish 8000:8000 -it scriptseed:latest" (should I update the documentation as well ?)

Note: Powershell is not available for Ubuntu 20.04 as a package, therefore prebuilt binaries are needed.

[mkasberg]

Oh, this is great! Love that you made the container work for serving the site locally too. I do think we should update the readme to reflect that as an option.

I think you broke the tests by changing the ENTRYPOINT in the Dockerfile. https://travis-ci.org/github/mkasberg/script-seed/builds/719719043

The tests use docker to run test.sh (see .travis.yml) - I suspect it's now simply serving the site with your entrypoint rather than running the tests and exiting. Maybe if you use CMD instead of ENTRYPOINT it will work?

[termdew]

I fixed it now. Now the tests run as entrypoint. After the tests, the Python2 server kicks in.

[mkasberg]

Looks great! Thanks!