contrib/docker/ubuntu.template

gpg: use 'wvfs' instead of 'wfile'

Method is about to be deprecated and the modern form is shorter.

FROM ubuntu:__CODENAME__
RUN apt-get update && apt-get install -y \
  build-essential \
  debhelper \
  dh-python \
  devscripts \
  python \
  python-all-dev \
  python-docutils \
  zip \
  unzip