require diagrams-lib >= 1.0.1 (for Hashable SizeSpec2D instance)

(cherry picked from commit a5a376ac2cd5e7e73af6f543ba56c9b574da2542)
Bump version to 1.0.1.2
Release notes for 1.0.1.2

(cherry picked from commit f318577880859be89b3fe6702605aaebd5239b29)