describe_features shows odd behavior for FsPeptide topology

[cxhernandez]

When I use DihedralFeaturizer on the FsPeptide dataset, some features seem to have incorrect descriptions:

>> DihedralFeaturizer().describe_features(trajectories[0])[77]
{'atominds': array([174, 176, 182, 184]),
 'featuregroup': 'psi',
 'featurizer': 'Dihedral',
 'otherinfo': 'cos',
 'resids': [16, 15],
 'resnames': ['ALA'],
 'resseqs': [16, 17]}

notice that the order of resids is wrong and resnames only has one residue name.