added header filetype checking
added header filetype checking

DigitalCoder/cartodb,thorncp/cartodb,raquel-ucl/cartodb,bloomberg/cartodb,raquel-ucl/cartodb,thorncp/cartodb,UCL-ShippingGroup/cartodb-1,nuxcode/cartodb,nuxcode/cartodb,CartoDB/cartodb,dbirchak/cartodb,DigitalCoder/cartodb,DigitalCoder/cartodb,codeandtheory/cartodb,thorncp/cartodb,UCL-ShippingGroup/cartodb-1,codeandtheory/cartodb,bloomberg/cartodb,CartoDB/cartodb,dbirchak/cartodb,codeandtheory/cartodb,bloomberg/cartodb,future-analytics/cartodb,raquel-ucl/cartodb,raquel-ucl/cartodb,nuxcode/cartodb,bloomberg/cartodb,nyimbi/cartodb,splashblot/dronedb,nyimbi/cartodb,nyimbi/cartodb,DigitalCoder/cartodb,UCL-ShippingGroup/cartodb-1,future-analytics/cartodb,splashblot/dronedb,future-analytics/cartodb,CartoDB/cartodb,UCL-ShippingGroup/cartodb-1,raquel-ucl/cartodb,thorncp/cartodb,nuxcode/cartodb,CartoDB/cartodb,nyimbi/cartodb,CartoDB/cartodb,dbirchak/cartodb,splashblot/dronedb,codeandtheory/cartodb,splashblot/dronedb,codeandtheory/cartodb,dbirchak/cartodb,UCL-ShippingGroup/cartodb-1,splashblot/dronedb,thorncp/cartodb,dbirchak/cartodb,future-analytics/cartodb,bloomberg/cartodb,DigitalCoder/cartodb,nyimbi/cartodb,nuxcode/cartodb,future-analytics/cartodb