release/96.0

• Add SPDI format for VEP (input) and Variant Recoder (input and output)
• Update VEP cache with gnomAD 2.1 (human)
• Update the Docker VEP base image to Ubuntu 18.04
• Retire deprecated flags: --gmaf, --maf_1kg, --maf_esp, --maf_exac, --check_alleles, --html, --gvf
• Retire legacy code about the pileup input format, which is no longer supported
• Deprecate the installation flag "--VERSION"
• Force numbers to be encoded as numbers in JSON output