relax 1.2.1

Description

This release fixes a number of bugs affecting the creation of Dasha scripts for specific model-free models (two time scale motions but without the τ_f parameter) and the reading of Dasha results for models with motions on two time scales. The function value.write which was broken when trying to write out relaxation data (R₁, R₂, or the NOE) has been fixed as well as the out of date generate_ri.py sample script.