Run output diff script

[Jakob37]

When testing dev changes, typically a run is redone after the changes.

It would be greatly convenient to have a script which can be pointed to output folders before and after the change.

This script could then check for:

• Whether all files are there, or whether removed / added
• Whether they are the same size / md5sums (wherever expected)
• For VCF files
  • If the header has changed (diff)
  • If the number of records have changed
  • What variants have been added / removed
• For BAM files
  • (Possibly) samtools flagstat
• For the final YAML file
  • The exact diff
  • Whether all paths resolve