According to this commit, the name was changed to butterdb about three months ago.
https://github.com/Widdershin/butterdb/commit/6a73c9199d53f5...
Digging on PyPI, I found the new package named butterdb. The version is bumped from .13 to .14, though that might just be the name change. In any case, it might be a good idea to change the submission to reflect the new name and the new package.