Generates tuples of spectra filename and corresponding output
    features from kronik

def mzmlfn_kronikfeature_generator(mzmlfns, kronikfns):
    """Generates tuples of spectra filename and corresponding output
    features from kronik"""
    for mzmlfn, kronikfn in zip(mzmlfns, kronikfns):
        for quant_el in generate_kronik_feats(kronikfn):
            yield os.path.basename(mzmlfn), quant_el