Merge pull request #168 from SciLifeLab/develop

Develop
Merge pull request #173 from SciLifeLab/develop

Develop - merge into master
Add functionality for merging vcf files. Currently does not add population frequency information. Partially fixes #190
Merge remote branch 'scilifelab/develop' into develop
Remove trailing tgt
Add variable to store information about demultiplex stats. Fixes issue #192
Merge branch 'hotfix/fix_demux_parsing' into develop
Merge pull request #191 from percyfal/develop

Develop - add support for merging vcf files