Incorrect version information found in setup.py

[jaraco]

I was reviewing setup.py as part of investigating another issue, when I noticed that version = "1.5.1" even on the 1.5.2 tag. I also noticed that setup.py references the tarball for 1.5.0. You may want to consider adopting setuptools_scm, which prevents these types of mistakes by having the version number defined in exactly one place (in the git tag).