spec UUIDObject#==
spec UUIDObject#to_h
UUIDObject#to_h: serialise Addr
Client#to_h: no need to custom-serialise addr
UUIDObject#to_h: serialise Project
Task#to_h: no need to custom-serialise project
UUIDObject#to_h: serialise Client
Registration#to_h: no need to custom-serialise
UUIDObject#to_h: serialise Task
Result#to_h: no need to custom-serialise
spec UUIDObject.from_h
UUIDObject.from_h: deserialise host and port
Client.from_h: no need to custom-deserialise host and port
UUIDObject.from_h: deserialise {client,project,task}_uuid
Registration.from_h: no need to custom-deserialise
Result.from_h: no need to custom-deserialise
Task.from_h: no need to custom-deserialise
spec Client#busy
drop Project.from_h spec
drop Project spec