switch to alpine-s6-python3 base img
switch to alpine-s6-python3 base img

cause linuxserver’s one is still python2.
Forked linuxservser’s and merge it with
  frolvlad/alpine-python3

Signed-off-by: Gaetan Semet <8ccd13098305f7fadd4fdccc2da60bfdfa8d8d20@xeberon.net>

Stibbons/dopplerr,Stibbons/dopplerr,Stibbons/dopplerr,Stibbons/dopplerr