get_phenotypes: get phenotpes
In frhl/our: genetic data analysis

Returns phenotypes for specific sets of individials based on their genotype and mutation.

get_phenotypes(
  data,
  reference,
  reference.suffix = ".txt",
  col.id = 1,
  col.variant = 6,
  col.gene = 11,
  get.contrasts = F
)

`data`	data input (df/dt)
`reference`	string directory input
`reference.suffix`	a string (e.g .txt)
`col.id`	integer. Column number for ID.
`col.variant`	integer. Column number for variant.
`col.gene`	integer. Column number for gene
`get.contrasts`	boolean. Should the data be contrasted? I.e. should the population be returned with a contrast label (KO/Not KO)?