function cleanData(originalData) {
            return originalData.reduce((acc, {day, hour, value}) => [
                ...acc,
                {
                    day: +day,
                    hour: +hour,
                    value: +value
                }
            ], []);
        }
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