MAINT: Update min required version to 3.7, and include 3.10

Bump required scipy version, due to dropped python 3.6

Mention in release notes

Closes #280.

MAINT: Remove deprecated functions and classes

Removing deprecrated functions and classes which were deprecated between 0.10.0 and 0.10.2.

Closes #282

DOC: Fix old imports in documentations

Include the gui in 'all' install

Fix the PytestRemovedIn8Warning