[DEVOPS-1121] explorer: add testnet URL to CORS origin whitelist
[DEVOPS-1121] explorer: add testnet URL to CORS origin whitelist

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