0.18

[MRG + 1] More versionadded everywhere! (#7403)

* insert versionadded versionchanged directives in docstrings for 0.18

indicate where exception classes were moved from

* moved versionadded in the proper places

0.17.1 release tag for DOI

This should be the same as 0.17.1, only re-created so zenodo mints a DOI