Register BioJulia types ?

[jonathanBieler]

Hi, I'd like to register some of the common file types used in bioinformatics. But I'd like to make sure it would be ok to take this extensions for FileIO before doing the work. All these files are very common in bioinformatics.

• .bed https://en.wikipedia.org/wiki/BED_(file_format) : the extension doesn't seem to have other common use, but there's no magic bytes for it (plain text with loose standard).
• .vcf (Variant Call Format): This one is ambiguous with "Virtual Contact File", but the file is supposed to always start with "##fileformat=VCF" (and this is enforced in our Julia loader) so I think we can add the magic argument for it.
• .fasta/fastq : no ambiguity for these (but no magic bytes either).
• GFF3 : no ambiguity (might be able to detect the header but not totally sure).

Would those be ok to add ? Thanks.

[StefanKarpinski]

These all seem good to me. The VCF one is slightly conflicting, but has magic, so that's good.

[jonathanBieler]

Thanks, I'll prepare a PR then (starting with BED I think).