message: feat(account-lib): updated casper sdk version to 1.0.19
  updated casper-client-sdk to version 1.0.19
  stlx-1666
diff: "bignumber.js": "^9.0.0",
  "blake2b": "git+https://github.com/BitGo/blake2b.git#6268e6dd678661e0acc4359e9171b97eb1ebf8ac",
  "bs58check": "^2.1.2",
  - "casper-client-sdk": "1.0.17",
  + "casper-client-sdk": "1.0.19",
  "elliptic": "^6.5.2",
  "ethereumjs-abi": "^0.6.5",
  "ethereumjs-tx": "2.1.2",
  