Added two HCs to support polyploid genomes; one to ensure that all toplevel sequences have a component_genome attribute, one to ensure only toplevel sequences have this atrtibute
Added two HCs to support polyploid genomes; one to ensure that all toplevel sequences have a component_genome attribute, one to ensure only toplevel sequences have this atrtibute

thomasmaurel/ensj-healthcheck,thomasmaurel/ensj-healthcheck,thomasmaurel/ensj-healthcheck,thomasmaurel/ensj-healthcheck,Ensembl/ensj-healthcheck,Ensembl/ensj-healthcheck,Ensembl/ensj-healthcheck,Ensembl/ensj-healthcheck