Resubmitting #239 from @hughsw to fix CI issues:

Use a single script, docker-test.sh to build an image and run a container to do testing.

This is a less intrusive, more focussed version of #234

$ ./docker-test.sh  --help

docker-test.sh -- Run standard bee-queue tests in a Docker container with a Redis server

Usage: docker-test.sh [command ...args]

The optional command and args specify what to run in the container (default: npm test).

You can use tools or run scripts from package.json, e.g.

  ./docker-test.sh  npx ava --serial --fail-fast --verbose --no-color --timeout 30000
  ./docker-test.sh  npm run coverage

If you want to work interactively in the container, run a shell, e.g.

  ./docker-test.sh  bash

Notes:
- The very first time this script is used it takes a while for Docker to
  download the base image and to populate its caches.
- You can ignore the Transparent Huge Pages warning from the Redis server.