Docker fixes

[ashmckenzie]

I noticed the Docker image was also affected by #689, so I set about fixing :)

[panghaichao]

hello,
I build success, but when I use ,the docker container exit!!!

[zerda]

@panghaichao You need modify the Dockerfile.

When build docker image, it's clone from github now, should copy files from local repo.

[bittner]

Can we merge this PR? This would be super-helpful. The Docker image will be built automatically, IIUC.

Maybe the image size also gets reduced by this, automagically, as suggested in #691.

[bittner]

NOTE: setup.py should probably read in requirements.txt after this PR is merged.

That would be sufficient:

def read_file(filename):
    with open(filename) as thefile:
        return thefile.read()

requires = read_file('requirements.txt')

[dcwangmit01]

This PR, in addition to pinning the Dockerfile image is required to make building this repo work.

FROM ubuntu:xenial

Until this repo starts getting maintained again, I've setup a Docker hub autobuild with this PR.

https://hub.docker.com/r/dcwangmit01/gateone/