Species List added to Study - Add new Fields #486

[BrapiCoordinatorSelby]

From @cpommier in #486

New Study fields

study.species: [
      "http://aims.fao.org/aos/agrovoc/c_8504"
    ]

In addition to commonCropnames. It brings controled vocabularies plus multispeces managment

[BrapiCoordinatorSelby]

Connected with #386 ?

[BrapiCoordinatorSelby]

I think this issue needs some more thought and discussion, it is not ready for V2.1