code: function cleanData(originalData) {
              return originalData.reduce((acc, {day, hour, value}) => {
                  return [
                      ...acc,
                      {
                          day: +day,
                          hour: +hour,
                          value: +value
                      }
                  ];
              }, []);
          }
docs: Cleaning data casting the values to the proper
  type while keeping the rest of properties on the data. It
  also creates a set of zeroed data (for animation purposes)
  @param   {HeatmapData} originalData  Raw data as passed to the container
  @return  {HeatmapData}               Clean data
  @private