Consider using setuptools_scm for versioning

[pllim]

setuptools_scm let you generate package version from tag, thus removing the need to hardcode version in places and also the risk of forgetting to manually bumping version during release.

astropy/astropy.github.com#491 (comment)

[pllim]

On this issue and some other packaging issues I mentioned, perhaps the setup shown in https://github.com/astropy/package-template or https://github.com/OpenAstronomy/packaging-guide might be useful. FYI.