Dockerfile for ubuntu

[caruccio]

Since original Dockerfile compiles against alpine's musl it creates a binary unusable outside the container. This Dockerfile.ubuntu builds a binary you can copy into your host without the need to install golang at all (which is desirable in a production etcd server).

$ sudo docker build . -t auger:latest -f Dockerfile.ubuntu
$ sudo docker run --rm --entrypoint cat auger:latest /go/bin/auger > auger
$ chmod +x ./auger
$ ./auger -h