message: Changed the Dockerfile for zcoin-builder
diff: -FROM ubuntu:14.04
  +FROM ubuntu:18.04
  # install required packages
  RUN apt-get update && apt-get install -y software-properties-common
  @@ -9,15 +9,7 @@ RUN apt-get update && apt-get install -y \
  autoconf automake bsdmainutils ccache cmake curl g++ g++-mingw-w64-x86-64 gcc gcc-mingw-w64-x86-64 git \
  libboost-all-dev libbz2-dev libcap-dev libdb4.8-dev libdb4.8++-dev libevent-dev libminiupnpc-dev libprotobuf-dev \
  libqrencode-dev libssl-dev libtool make pkg-config protobuf-compiler python-pip qtbase5-dev \
  - qttools5-dev-tools python3-zmq zlib1g-dev build-essential
  -
  -# Install minizip from source (unavailable from apt)
  -RUN curl -L https://www.zlib.net/zlib-1.2.11.tar.gz | tar -xz -C /tmp && \
  - cd /tmp/zlib-1.2.11/contrib/minizip && \
  - autoreconf -fi && \
  - ./configure --enable-shared=no --with-pic && \
  - make -j$(nproc) install && \
  - cd / && rm -rf /tmp/zlib-1.2.11
  + qttools5-dev-tools python3-zmq zlib1g-dev build-essential minizip
  # Install zmq from source (outdated version on apt)
  RUN curl -L https://github.com/zeromq/libzmq/releases/download/v4.3.1/zeromq-4.3.1.tar.gz | tar -xz -C /tmp && \
  