[BUG] --install-options are suppressed by pip 20.2.3

May not be a bug but I would like to just to inform that documentation may not be up to date. And maybe you may want to do some changes (in code or docs) so that latest version of pip 20.2.3 can aligned.

Describe the bug
When using latest version of pip 20.2.3. --install-options containing paths are no longer supported.
See also https://github.com/pypa/pip/issues/7309

To Reproduce
When running as decribed in DOCS one will see an error:

pip install --upgrade pip==20.2.3 
pip install graphite-web==1.1.7 --install-option="--prefix=/srv/graphite" --install-option="--install-lib=/srv/graphite/webapp"

ERROR: Location-changing options found in --install-option: ['--install-lib', '--prefix'] from command line. This is unsupported, use pip-level options like --user, --prefix, --root, and --target instead.

Environment (please complete the following information):

• OS flavor: Ubuntu 18.04 using Docker
• Graphite-web version: 1.1.7
• Django/Python version: 3.7
• Setup type: pip 20.2.3