add script to clean up Yum cache
add script to clean up Yum cache

ChicagoBoothAnalytics/HelpRFun,ChicagoBoothAnalytics/DataWrangling_inR,ChicagoBoothAnalytics/DataWrangling_inR,ChicagoBoothAnalytics/HelpRFun,ChicagoBoothAnalytics/DataWrangling_inR,ChicagoBoothAnalytics/HelpRFun