message: python2 packages have been removed
diff: @@ -26,8 +26,8 @@ RUN set -e; \
  build-essential g++-9 ninja-build \
  # CI dependencies
  git ssh tar gzip ca-certificates gnupg \
  - # Pythons
  - python-pip python3-pip python-setuptools python3-setuptools python-dev \
  + # Python3
  + python3-pip python3-setuptools\
  # other
  curl file gdb gdbserver ccache python3.6-dev \
  gcovr cppcheck doxygen rsync graphviz graphviz-dev unzip vim zip pkg-config; \
  @@ -80,7 +80,6 @@ RUN set -e; \
  # python bindings dependencies
  RUN set -e; \
  - pip install grpcio_tools pysha3; \
  pip3 install grpcio_tools pysha3 iroha==0.0.5.4
  # install lcov
  