code: def _resolveambig(subseq):
      
      N = []
      for col in subseq:
          rand = np.random.binomial(1, 0.5)
          N.append([_AMBIGS[i][rand] for i in col])
      return np.array(N)
docs: Randomly resolves iupac hetero codes. This is a shortcut
      for now, we could instead use the phased alleles in RAD loci.