Support starting as Docker container

[nicokaiser]

This Dockerfile snippet builds a Docker container with the service. However, camera access is not possible at the moment (raspistill works, but cannot find a camera despite passing through the device or even starting with --privileged).

FROM arm32v6/node:8-alpine
ADD ./package.json /app/
RUN apk add --no-cache python2 make g++ raspberrypi raspberrypi-dev \
  && cd /app \
  && npm install --production \
  && apk del --no-cache python2 make g++
WORKDIR /app
ADD . /app/
VOLUME /capture
EXPOSE 4443
CMD ["npm", "start"]