code: function getClassNames(props) {
    return Object.keys(props).
      filter(key => classMap[key]).
      map(key => styles[Number.isInteger(props[key]) ? `${classMap[key]}-${props[key]}` : classMap[key]]);
  }
docs: Converts props like "xs=9 xsOffset={2}" to classes "col-xs-9 col-xs-offset-2"
  @param {Object} props incoming props
  @returns {Array} result classnames