do not croak if a Bustard_Summary file does not exist
made interop parsing code more generic and modified tests as appropriate
Merge pull request #17 from srl147/devel

Devel
Merge pull request #4 from wtsi-npg/devel

devel
added sanger168_7.tags for 7-base index reads
use length of index read from tag0 bam file rather than length of tag in
decode metrics file to derive barcode file, added new tests and test data
add changes for release 56.6
added tag_sets data sub-directory to MANIFEST
Merge pull request #18 from srl147/devel

use length of index read from tag0 bam file rather than length of tag in
decode metrics file to derive barcode file, added new tests and test data
Changes update prior to the release
Merge pull request #19 from wtsi-npg/devel

pull from wtsi devel to master: create release 56.6