message: Fix to point to the latest gcc & g++ version.
diff: @@ -57,6 +57,10 @@ sudo make all install
  export LD_LIBRARY_PATH=/usr/local/lib/openmpi
  sudo ldconfig
  +sudo update-alternatives --install /usr/bin/gcc gcc /dt7/usr/bin/gcc 60 --slave /usr/bin/g++ g++ /dt7/usr/bin/g++
  +
  +g++ --version
  +
  # Install Horovod.
  cd ..
  HOROVOD_WITH_TENSORFLOW=1
  