add a sourmash module

[fmalmeida]

Add an additional module for scanning the sample using sourmash:

• [x] scan against refseq using whole genome (LCA)
• [x] an option to create a simple phylogeny using sourmash against the N closest genomes detected in the pipeline using refseq_masher module or against genomes provided by user in a directory
• [ ] Include results in HTML reports