panoptes: 2.0.alpha8

Eighth alpha release of the Panoptes 2.0 series. This release adds genotypes and flexible maps, completing the the major components. We expect to move to beta for the next release. Breaking changes: Reference summaries are now only supported in the "combined" format. This is in preparation for them to become full tables at a later date. This release includes: Features: #384 - Genotypes channel, with new drawing technique ~20x faster than 1.6.2. #430 - Leaflet based maps, supports flexible map creation in templates and raster layers such as prevalence data #454 - Reinstate ref genome summaries, supporting only the combined data format Fixes: None, feature-focused release. Known issues: Trees cannot be accessed