s3 location for common genome+annotation combinations

[kopardev]

• prebuild reference files for common genome+annotations and store in s3
• json file will have s3 URIs
• json file itself will be s3 URI ... make --genome CL argument work with custom json which are themselves located in s3

[kopardev]

download subcommand to make a local copy of the resources and regenerate a local json to point to the local copies.