✂️ Remove Dockerfile and Compose file

They're not valid anymore, and fixing them would require quite a lot of
work, since we drastically changed the way we provision things. I'm
removing them rather than leaving a completely broken thing.

prepare-labs/Dockerfile

@@ -1,30 +0,0 @@
-FROM debian:jessie
-MAINTAINER AJ Bowen <aj@soulshake.net>
-
-RUN apt-get update && apt-get install -y \
-    bsdmainutils \
-    ca-certificates \
-    curl \
-    groff \
-    jq \
-    less \
-    man \
-    pssh \
-    python \
-    python-docutils \
-    python-pip \
-    ssh \
-    wkhtmltopdf \
-    xvfb \
-    --no-install-recommends \
-    && rm -rf /var/lib/apt/lists/*
-
-RUN pip install \
-    awscli \
-    jinja2 \
-    pdfkit \
-    PyYAML \
-    termcolor
-
-RUN mv $(which wkhtmltopdf) $(which wkhtmltopdf).real
-COPY lib/wkhtmltopdf /usr/local/bin/wkhtmltopdf

prepare-labs/README.md

@@ -45,9 +45,6 @@ These require Python 3. If you are on a Mac, see below for specific instructions
 Python 3 to be the default Python on a Mac. In particular, if you installed `mosh`, Homebrew
 may have changed your default Python to Python 2.
 
-If you don't or can't install these requirements, you
-can also run this script in a Docker image.
-
 You will also need an account with the cloud provider(s) that you want to use to deploy the lab environments.
 
 ## Cloud provider account(s) and credentials

prepare-labs/docker-compose.yml

@@ -1,19 +0,0 @@
-version: "2"
-
-services:
-    workshopctl:
-        build: .
-        image: workshopctl
-        working_dir: /root/prepare-vms
-        volumes:
-            - $HOME/.aws/:/root/.aws/
-            - $SSH_AUTH_SOCK:$SSH_AUTH_SOCK
-            - $PWD/:/root/prepare-vms/
-        environment:
-            SSH_AUTH_SOCK: ${SSH_AUTH_SOCK}
-            AWS_ACCESS_KEY_ID: ${AWS_ACCESS_KEY_ID}
-            AWS_SECRET_ACCESS_KEY: ${AWS_SECRET_ACCESS_KEY}
-            AWS_DEFAULT_REGION: ${AWS_DEFAULT_REGION}
-            AWS_INSTANCE_TYPE: ${AWS_INSTANCE_TYPE}
-            USER: ${USER}
-        entrypoint: /root/prepare-vms/workshopctl

prepare-labs/lib/commands.sh

@@ -14,16 +14,6 @@ _cmd_help() {
     printf "%s" "$HELP" | sort
 }
 
-_cmd build "Build the Docker image to run this program in a container"
-_cmd_build() {
-    docker-compose build
-}
-
-_cmd wrap "Run this program in a container"
-_cmd_wrap() {
-    docker-compose run --rm labctl "$@"
-}
-
 _cmd cards "Generate ready-to-print cards for a group of VMs"
 _cmd_cards() {
     TAG=$1