BAM header to_hashmap() fails on CO records

[andrewpatto]

Just in doing some work on printing example BAM headers - and thought we'd use to_hashmap() to get us the header data nicely split up. But it appears to be panicking on the unwrap() at line 88 of src/bam/header.rs

let cap = TAG_RE.captures(part).unwrap();

which would make sense as the TAG_RE expects to see a colon, but the comment records do not necessarily fit that pattern

For example, the public cram

"s3://1000genomes/data/NA18616/alignment/NA18616.alt_bwamem_GRCh38DH.20150718.CHB.low_coverage.cram"

has some header records

"@co\tFASTQ=ERR009378_1.fastq.gz",

without investigating any further, my guess is that those are the records that are failing. I'm not enough of a bioinformatics expect to know if it is the headers themselves at fault, so I'll just leave it here as an issue.

[andrewpatto]

@brainstorm follow up to the lambda example