message: RestClient posts with JSON-encoded StdTx
diff: -import { unmarshalTx } from "@tendermint/amino-js";
  +import { Encoding } from "@iov/encoding";
  import axios, { AxiosInstance } from "axios";
  -import { AminoTx, BaseAccount } from "./types";
  +import { AminoTx, BaseAccount, isAminoStdTx } from "./types";
  +
  +const { fromUtf8 } = Encoding;
  interface NodeInfo {
  readonly network: string;
  @@ -157,10 +159,15 @@ export class RestClient {
  return responseData as TxsResponse;
  }
  + // tx must be JSON encoded StdTx (no wrapper)
  public async postTx(tx: Uint8Array): Promise<PostTxsResponse> {
  - const unmarshalled = unmarshalTx(tx, true);
  + // TODO: check this is StdTx
  + const decoded = JSON.parse(fromUtf8(tx));
  + if (!isAminoStdTx(decoded)) {
  + throw new Error("Must be json encoded StdTx");
  + }
  const params = {
  - tx: unmarshalled.value,
  + tx: decoded,
  mode: this.mode,
  };
  const responseData = await this.post("/txs", params);
  