slightly longer error for malformed bed record

src/repeats.rs

@@ -39,7 +39,7 @@ impl RepeatIntervalIterator {
         let mut reader = bed::Reader::from_file(region_file).expect("Problem reading bed file!");
         let mut data = Vec::new();
         for record in reader.records() {
-            let rec = record.expect("Error reading bed record.");
+            let rec = record.expect("Error reading bed record. Please verify bed file is in the correct format and without header.");
             let repeat = RepeatInterval::from_bed(&rec, fasta);
             if let Some(repeat) = repeat {
                 data.push(repeat);