mainnet-staging-short-epoch-genesis.json:  drop all but three core nodes
mainnet-staging-short-epoch-genesis.json:  drop all but three core nodes

input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/pos-haskell-prototype,input-output-hk/pos-haskell-prototype