message: Switch back to use easy_install to install pip2 and pip3, but let pip be upgraded to the latest by not specifying the version.
diff: set -e
  # Get the latest version of pip so it recognize manylinux2010
  -pip2 install --upgrade pip
  -pip3 install --upgrade pip
  +easy_install3 -U pip
  +easy_install -U pip
  # Install pip packages from whl files to avoid the time-consuming process of
  # building from source.
  