parseCsv = async (data) => {
  return new Promise(resolve => {
    data = data.map((row) => {
      return Object.keys(row).map(key => parseFloat(row[key]));
    });
    resolve(data);
  });
}
Given CSV data returns an array of arrays of numbers.

@param {Array<Object>} data Downloaded data.

@returns {Promise.Array<number[]>} Resolves to data with values parsed as floats.