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
{
    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
    CWallet* const pwallet = wallet.get();
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
    if (request.fHelp || request.params.size() != 1) {
        throw std::runtime_error(
            RPCHelpMan{"getaddressinfo",
                "\nReturn information about the given bitcoin address. Some information requires the address\n"
                "to be in the wallet.\n",
                {
                    {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The bitcoin address to get the information of."},
                },
                RPCResult{
            "{\n"
            "  \"address\" : \"address\",        (string) The bitcoin address validated\n"
            "  \"scriptPubKey\" : \"hex\",       (string) The hex-encoded scriptPubKey generated by the address\n"
            "  \"ismine\" : true|false,        (boolean) If the address is yours or not\n"
            "  \"iswatchonly\" : true|false,   (boolean) If the address is watchonly\n"
            "  \"solvable\" : true|false,      (boolean) Whether we know how to spend coins sent to this address, ignoring the possible lack of private keys\n"
            "  \"desc\" : \"desc\",            (string, optional) A descriptor for spending coins sent to this address (only when solvable)\n"
            "  \"isscript\" : true|false,      (boolean) If the key is a script\n"
            "  \"ischange\" : true|false,      (boolean) If the address was used for change output\n"
            "  \"iswitness\" : true|false,     (boolean) If the address is a witness address\n"
            "  \"witness_version\" : version   (numeric, optional) The version number of the witness program\n"
            "  \"witness_program\" : \"hex\"     (string, optional) The hex value of the witness program\n"