message: Change base image from ubuntu:16.04 to ubuntu:14.04 due to our Gitian use 14.04
diff: -FROM ubuntu:16.04
  +FROM ubuntu:14.04
  # install required packages
  RUN apt-get update && apt-get install -y software-properties-common
  @@ -11,8 +11,6 @@ RUN apt-get update && apt-get install -y \
  libqrencode-dev libssl-dev libtool libzmq3-dev make pkg-config protobuf-compiler python-pip qtbase5-dev \
  qttools5-dev-tools python3-zmq
  -RUN update-alternatives --set x86_64-w64-mingw32-g++ /usr/bin/x86_64-w64-mingw32-g++-posix
  -
  RUN pip install ez_setup
  # create user to use
  