fix fwrite file size test for windows where its 34 bytes bigger. #580
fix fwrite file size test for windows where its 34 bytes bigger. #580

vlulla/data.table,jangorecki/data.table,Rdatatable/data.table,vlulla/data.table,jangorecki/data.table,vlulla/data.table,Rdatatable/data.table,Rdatatable/data.table,vlulla/data.table,Rdatatable/data.table,jangorecki/data.table,jangorecki/data.table