delete Dockerfile: broken, and I think it's for the server anyways

The servers were moved out to separate repos (magic-wormhole-mailbox-server
and magic-wormhole-transit-relay), and I think this Dockerfile was building
an image mostly to run the mailbox server.

It might make sense in the future to have a Docker image for just the client,
in which case it'll be time to bring these Dockerfiles back with different
contents.

refs #295

.dockerignore

@@ -1 +0,0 @@
-dist

Dockerfile

@@ -1,89 +0,0 @@
-#
-# Attempts are made to follow the guidelines at
-# https://docs.docker.com/engine/userguide/eng-image/dockerfile_best-practices/
-#
-
-FROM library/ubuntu:16.04
-
-# If there are security updates for any of the packages we install,
-# bump the date in this environment variable to invalidate the Docker
-# build cache and force installation of the new packages.  Otherwise,
-# Docker's image/layer cache may prevent the security update from
-# being retrieved.
-ENV SECURITY_UPDATES="2017-15-01"
-
-# Tell apt/dpkg/debconf that we're non-interactive so it won't write
-# annoying warnings as it installs the software we ask for.  Making
-# this an `ARG` sets it in the environment for the duration of the
-# _build_ only - preventing this from having any effect on a container
-# running this image (which shouldn't really be installing more
-# software but who knows...).
-ARG DEBIAN_FRONTEND=noninteractive
-
-# We'll do an upgrade because the base Ubuntu image isn't guaranteed
-# to include the latest security updates.  This is counter to best
-# practice recommendations but security updates are important.
-RUN apt-get --quiet update && \
-    apt-get --quiet install -y unattended-upgrades && \
-    unattended-upgrade --minimal_upgrade_steps && \
-rm -rf /var/lib/apt/lists/*
-
-# libffi-dev should probably be a build-dep for python-nacl and python-openssl
-# but isn't for some reason.  Also, versioneer depends on the git cli to
-# compute the source version.
-RUN apt-get --quiet update && apt-get --quiet install -y \
-    libffi-dev \
-    python-virtualenv \
-    git \
-&& rm -rf /var/lib/apt/lists/*
-
-# Source repositories seem to be disabled on the Xenial image now.  Enable
-# them so we can actually get some build deps.
-RUN sed -i -e 's/^# deb-src/deb-src/' /etc/apt/sources.list
-
-# magic-wormhole depends on these and pip wants to build them both from
-# source.
-RUN apt-get --quiet update && apt-get --quiet build-dep -y \
-    python-openssl \
-    python-nacl \
-&& rm -rf /var/lib/apt/lists/*
-
-# Create a virtualenv into which to install magicwormhole in to.
-RUN virtualenv /app/env
-
-# Get a newer version of pip.  The version in the virtualenv installed from
-# Ubuntu might not be very recent, depending on when the build happens.
-RUN /app/env/bin/pip install --upgrade pip
-
-# Create a less privileged account to actually use to run the server.
-ENV WORMHOLE_USER_NAME="wormhole"
-
-# Force the allocated user to uid 1000 because we hard-code 1000 below.
-RUN adduser --uid 1000 --disabled-password --gecos "" "${WORMHOLE_USER_NAME}"
-
-# Facilitate network connections to the application.  The rendezvous server
-# listens on 4000 by default.
-EXPOSE 4000
-
-# Put the source somewhere pip will be able to see it.
-ADD . /magic-wormhole
-
-# Get the app we want to run!
-WORKDIR /magic-wormhole
-RUN /app/env/bin/pip install .
-
-# Run the application with this working directory.
-WORKDIR /app/run
-
-# And give it to the user the application will run as.
-RUN chown ${WORMHOLE_USER_NAME} /app/run
-
-# Switch to a non-root user.
-USER 1000
-
-# This makes starting a server succinct.
-ENTRYPOINT ["/app/env/bin/wormhole-server", "start", "--no-daemon"]
-
-# By default, start up a pretty reasonable server.  This can easily be
-# overridden by another command which will get added to the entrypoint.
-CMD ["--rendezvous", "tcp:4000"]