Reported here: https://github.com/bitcoin/bitcoin/pull/10244#issuecomment-378035305

Travis log here: https://travis-ci.org/bitcoin/bitcoin/jobs/361243719#L2810

Note the JSON exception:

```
test_framework.authproxy.JSONRPCException: The mempool was not loaded yet (-1) 
```

That exception was introduced here: https://github.com/bitcoin/bitcoin/commit/cb1e319fe9e198c9c5cf5236fe9af5a3d748b9e8#diff-a0c8f511d90e83aa9b5857e819ced344R1617

cc @jtimon 
{
    if (verbose) {
        LOCK(pool.cs);
        UniValue o(UniValue::VOBJ);
        for (const CTxMemPoolEntry& e : pool.mapTx) {
            const uint256& hash = e.GetTx().GetHash();
            UniValue info(UniValue::VOBJ);
            entryToJSON(pool, info, e);
            o.pushKV(hash.ToString(), info);
        }
        return o;
    } else {
        std::vector<uint256> vtxid;
        pool.queryHashes(vtxid);
        UniValue a(UniValue::VARR);
        for (const uint256& hash : vtxid)
            a.push_back(hash.ToString());
        return a;
    }
}
static UniValue getrawmempool(const JSONRPCRequest& request)
{
    if (request.fHelp || request.params.size() > 1)