travis run: https://travis-ci.org/bitcoin/bitcoin/jobs/406813397

```
rpc_psbt.py failed, Duration: 4 s
stdout:
2018-07-22T13:28:57.765000Z TestFramework (INFO): Initializing test directory /tmp/bitcoin_test_runner_20180722_132530/rpc_psbt_49
2018-07-22T13:29:00.531000Z TestFramework (ERROR): Assertion failed
Traceback (most recent call last):
  File "/home/travis/build/bitcoin/bitcoin/build/bitcoin-x86_64-unknown-linux-gnu/test/functional/test_framework/test_framework.py", line 160, in main
    self.run_test()
  File "/home/travis/build/bitcoin/bitcoin/build/bitcoin-x86_64-unknown-linux-gnu/test/functional/rpc_psbt.py", line 101, in run_test
    assert_raises_rpc_error(-22, "TX decode failed", self.nodes[0].converttopsbt, signedtx['hex'])
  File "/home/travis/build/bitcoin/bitcoin/build/bitcoin-x86_64-unknown-linux-gnu/test/functional/test_framework/util.py", line 105, in assert_raises_rpc_error
    assert try_rpc(code, message, fun, *args, **kwds), "No exception raised"
AssertionError: No exception raised
const RPCHelpMan help{"sendmany",
                "\nSend multiple times. Amounts are double-precision floating point numbers." +
                    HelpRequiringPassphrase(pwallet) + "\n",
                {
                    {"dummy", RPCArg::Type::STR, RPCArg::Optional::NO, "Must be set to \"\" for backwards compatibility.", "\"\""},
                    {"amounts", RPCArg::Type::OBJ, RPCArg::Optional::NO, "A json object with addresses and amounts",
                        {
                            {"address", RPCArg::Type::AMOUNT, RPCArg::Optional::NO, "The bitcoin address is the key, the numeric amount (can be string) in " + CURRENCY_UNIT + " is the value"},
                        },
                    },
                    {"minconf", RPCArg::Type::NUM, RPCArg::Optional::OMITTED_NAMED_ARG, "Ignored dummy value"},
                    {"comment", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "A comment"},
                    {"subtractfeefrom", RPCArg::Type::ARR, RPCArg::Optional::OMITTED_NAMED_ARG, "A json array with addresses.\n"
            "                           The fee will be equally deducted from the amount of each selected address.\n"
            "                           Those recipients will receive less bitcoins than you enter in their corresponding amount field.\n"
            "                           If no addresses are specified here, the sender pays the fee.",
                        {
                            {"address", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "Subtract fee from this address"},
                        },
                    },
                    {"replaceable", RPCArg::Type::BOOL,  "fallback to wallet's default", "Allow this transaction to be replaced by a transaction with higher fees via BIP 125"},
                    {"conf_target", RPCArg::Type::NUM,  "fallback to wallet's default", "Confirmation target (in blocks)"},
                    {"estimate_mode", RPCArg::Type::STR,  "UNSET", "The fee estimate mode, must be one of:\n"
            "       \"UNSET\"\n"
            "       \"ECONOMICAL\"\n"
            "       \"CONSERVATIVE\""},
                },
                 RPCResult{
            "\"txid\"                   (string) The transaction id for the send. Only 1 transaction is created regardless of \n"
            "                                    the number of addresses.\n"