OPSK-36 - built tests for the core synchronisation behaviour and implemented

edge cases also need testing, but the core behaviour is working.
OPSK-36 updated rake task for ontology synchronisation
OPSK-36 handle suggested types when the type of assay changes according the ontology

if it means changing from modelling to experimental assay, or vice versa, the suggested type
remains, and remains linked to the assay, but has its label updated
refactoring and code tidying up