Describe loci in a scheme

[lskatz]

Need file to describe all the loci in a scheme. Otherwise callers cannot output a proper profiles file and know all the loci it missed. I'm sure there are other reasons.

One way to do this would be to make it a yaml file and define the yaml file in the spec.

Here is a first shot at it.

scheme: senterica
  - loci:
    - aroC
    - dnaN
    - hemD
    - hisD
    - purE
    - sucA
    - thrA

I could potentially add in locus properties too, following what BigsDB does as shown here:

And more context here.