pip-tools and pip-review just look at your installed dependencies and upgrade them, they don't update your requirements.txt file.

Upgrading packages doesn't work for me because I need my build scripts to do the upgrade. For example, when installing some packages which have C bindings they fail unless certain flags are set correctly.

Requires.io is cool, I personally use Gemnasium [1] for the same thing. However, both tools don't update your requirements.txt file for you, they just notify you when you need to update it.

[1] https://gemnasium.com/features