release 0.3.x

[mschubert]

Things to consider before releasing v0.3.x:

• Fix intron-exon boundary variants removed because unclear which sequence
• Automatically handle GRCh38/hg38 genome mismatches
• Test common sample sheet errors
  • Missing columns
  • Empty rows
  • Allowed characters for sample IDs? (e.g. -)
• Test common minigene report errors
  • Missing columns
  • Mismatch between sheet name and samplesheet library
• Throw error, not warning, if fusion combines different genomes
• Find a solution for mut_id