broadinstitute/viral-ngs: v1.21.1

New: Changed: in WDL workflows, default demultiplexing parameters to support novaseq [#868] in illumina.py::illumina_demux: max_mismatches changed 0 -> 1, and minimum_base_quality: 25 -> 10 This supports the four Q scores written by the Novaseq Upgraded: samtools (and htslib) 1.7 -> 1.9 [#870] pysam 0.14.1 -> 0.15.0 [#870] picard 2.18.9 -> 2.18.11 [#869