Reduce python container size by compiling with pip

pip_compile_snippet.Dockerfile

# Install python packages with pip using compilation to reduce size
# - https://towardsdatascience.com/how-to-shrink-numpy-scipy-pandas-and-matplotlib-for-your-data-product-4ec8d7e86ee4
# - https://avilpage.com/2020/02/reduce-python-package-footprint.html
# - https://stackoverflow.com/a/22942120
# - https://blog.mapbox.com/aws-lambda-python-magic-e0f6a407ffc6
# `/usr/local/bin/python3-config --cflags` should be applied automatically, the
#  following flags extend these.
RUN pip install --upgrade pip \
  && export CFLAGS="${CFLAGS} -g0 -Wl,--strip-all -Os -I/usr/include:/usr/local/include" \
  && export LDFLAGS="${LDFLAGS} -L/usr/lib:/usr/local/lib" \
  && pip install \
      --no-cache-dir \
      --trusted-host pypi.python.org \
      --compile \
      --global-option=build_ext \
      --global-option="-j 8" \
      --requirement /tmp/requirements.txt