add -L option to raise cutoff to allow indel calling

[danrlu]

• [x ] This comment contains a description of changes (with reason)
• [x ] If you've fixed a bug or added code that should be tested, add tests!
• [x ] Ensure the test suite passes (nextflow run . -profile test,docker).

Added -L 1000000 to enable INDEL calling in vcf generation (see issue here). Tested with seq69/70 data and tests in github actions.

[neevor]

Sorry I completely missed that I should review this PR!

[danrlu]

No worries at all!! It's a very simple fix, just wanted to make sure you're aware of the change :) Thanks Aaron!!