release 2.9.0 of the MDAnalysis UserGuide

release 2.8.0 of the MDAnalysis UserGuide

Skip stderr checks in nbval (#358)

* Add conftest

* temporarily disable snapshot test

* Add init file

* move conftest, fix up deprecated flags

* Add the conftest file properly

* pull back everything but stderr

* make it a tuple

* fix various hook issues

* bring back snapshots

* revert typos

release 2.6.1 of the MDAnalysis Userguide

release 2.6.0 of the MDAnalysis UserGuide

release 2.5.0 of the MDAnalysis Userguide

release 2.4.3 of the MDAnalysis Userguide

release 2.4.2 of the MDAnalysis Userguide

release 2.4.1 of the MDAnalysis Userguide

release 2.4.0 of the MDAnalysis Userguide