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
UniValue importmulti(const JSONRPCRequest& request);
static const CRPCCommand commands[] =
{ 
    
    { "rawtransactions",    "fundrawtransaction",               &fundrawtransaction,            {"hexstring","options","iswitness"} },
    { "wallet",             "abandontransaction",               &abandontransaction,            {"txid"} },
    { "wallet",             "abortrescan",                      &abortrescan,                   {} },
    { "wallet",             "addmultisigaddress",               &addmultisigaddress,            {"nrequired","keys","label","address_type"} },
    { "wallet",             "backupwallet",                     &backupwallet,                  {"destination"} },
    { "wallet",             "bumpfee",                          &bumpfee,                       {"txid", "options"} },
    { "wallet",             "createwallet",                     &createwallet,                  {"wallet_name", "disable_private_keys", "blank"} },
    { "wallet",             "dumpprivkey",                      &dumpprivkey,                   {"address"}  },
    { "wallet",             "dumpwallet",                       &dumpwallet,                    {"filename"} },
    { "wallet",             "encryptwallet",                    &encryptwallet,                 {"passphrase"} },
    { "wallet",             "getaddressesbylabel",              &getaddressesbylabel,           {"label"} },
    { "wallet",             "getaddressinfo",                   &getaddressinfo,                {"address"} },
    { "wallet",             "getbalance",                       &getbalance,                    {"dummy","minconf","include_watchonly"} },
    { "wallet",             "getnewaddress",                    &getnewaddress,                 {"label","address_type"} },
    { "wallet",             "getrawchangeaddress",              &getrawchangeaddress,           {"address_type"} },
    { "wallet",             "getreceivedbyaddress",             &getreceivedbyaddress,          {"address","minconf"} },
    { "wallet",             "getreceivedbylabel",               &getreceivedbylabel,            {"label","minconf"} },
    { "wallet",             "gettransaction",                   &gettransaction,                {"txid","include_watchonly"} },
    { "wallet",             "getunconfirmedbalance",            &getunconfirmedbalance,         {} },
    { "wallet",             "getwalletinfo",                    &getwalletinfo,                 {} },
    { "wallet",             "importaddress",                    &importaddress,                 {"address","label","rescan","p2sh"} },
    { "wallet",             "importmulti",                      &importmulti,                   {"requests","options"} },
    { "wallet",             "importprivkey",                    &importprivkey,                 {"privkey","label","rescan"} },
    { "wallet",             "importprunedfunds",                &importprunedfunds,             {"rawtransaction","txoutproof"} },
    { "wallet",             "importpubkey",                     &importpubkey,                  {"pubkey","label","rescan"} },
    { "wallet",             "importwallet",                     &importwallet,                  {"filename"} },