support $HEZ erc20 token

We want to add support for $HEZ ERC-20 token from Hermez before EThCC

Here are details about the token

    {
      "chainId": 1,
      "address": "0xEEF9f339514298C6A857EfCfC1A762aF84438dEE",
      "symbol": "HEZ",
      "name": "Hermez Network",
      "decimals": 18,
      "logoURI": "ipfs://QmRkKW7dM9eGYnPuvR16eMiwJoGPZagaXV28tU13zbDBD4",
      "tags": []
    }