code: function limitUpdate (limit, update) {
    la(check.fn(limit), 'expected limit function', limit)
  
    const filter = R.filter(version => limit(update.name, version))
  
    return R.evolve({
      versions: filter
    })(update)
  }
docs: /*
  update is an object like this
  {
  name: 'check-types',
  versions: ['0.7.0', '0.7.1']
  }
  and limit function tells for each (name, version) if it should remain
  in this list