#16 Subtask - create GA4GH prefixes .yaml

[ahwagner]

Create a yaml file for prefix registration and use with resolver service.

[tcezard]

I saw the PR #70 documenting how the prefix is meant to be registered but still have some questions:

Within refget: Sequence collections we're generating identifiers for the main collection (referred as level 0) and for the component (referred as level 1).
The ways of providing name space for the level 0 would be something like ga4gh:SC.ucvvsklhda834nsdnskdsjs56dadsa and for the level 1 ga4gh:SC.sequences.GcvcduyYdfwLVXZerYRejhGdaj3 where sequences is the type of component.

The question are then:

• Would we have to register all the different possible types SC, SC.sequences, SC.name, etc ?
• Do you imagine that the (hypothetical) GA4GH resolver would only resolve the SC or be able to resolve subtypes as well ?

See issue ga4gh/refget#53.