message: adds alsa-utils to docker image, allowing us to control audio output
diff: @@ -46,6 +46,7 @@ RUN apk add --update \
  py3-zmq \
  py3-urwid \
  py3-numpy \
  + alsa-utils \
  && rm -rf /var/cache/apk/*
  # Resin's python base container compiles python from scratch and doesn't have
  