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
{
    if (request.fHelp || request.params.size() != 1) {
        throw std::runtime_error(
            RPCHelpMan{"analyzepsbt",
            "\nAnalyzes and provides information about the current status of a PSBT and its inputs\n",
            {
                {"psbt", RPCArg::Type::STR, RPCArg::Optional::NO, "A base64 string of a PSBT"}
            },
            RPCResult {
                "{\n"
                "  \"inputs\" : [                      (array of json objects)\n"
                "    {\n"
                "      \"has_utxo\" : true|false     (boolean) Whether a UTXO is provided\n"
                "      \"is_final\" : true|false     (boolean) Whether the input is finalized\n"
                "      \"missing\" : {               (json object, optional) Things that are missing that are required to complete this input\n"
                "        \"pubkeys\" : [             (array, optional)\n"
                "          \"keyid\"                 (string) Public key ID, hash160 of the public key, of a public key whose BIP 32 derivation path is missing\n"
                "        ]\n"
                "        \"signatures\" : [          (array, optional)\n"
                "          \"keyid\"                 (string) Public key ID, hash160 of the public key, of a public key whose signature is missing\n"
                "        ]\n"
                "        \"redeemscript\" : \"hash\"   (string, optional) Hash160 of the redeemScript that is missing\n"
                "        \"witnessscript\" : \"hash\"  (string, optional) SHA256 of the witnessScript that is missing\n"
                "      }\n"
                "      \"next\" : \"role\"             (string, optional) Role of the next person that this input needs to go to\n"
                "    }\n"
                "    ,...\n"
                "  ]\n"
                "  \"estimated_vsize\" : vsize       (numeric, optional) Estimated vsize of the final signed transaction\n"
                "  \"estimated_feerate\" : feerate   (numeric, optional) Estimated feerate of the final signed transaction in " + CURRENCY_UNIT + "/kB. Shown only if all UTXO slots in the PSBT have been filled.\n"