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 (gArgs.GetBoolArg("-stopafterblockimport", DEFAULT_STOPAFTERBLOCKIMPORT)) {
        LogPrintf("Stopping after block import\n");
        StartShutdown();
        return;
    }
    } 
    if (gArgs.GetArg("-persistmempool", DEFAULT_PERSIST_MEMPOOL)) {
        LoadMempool();
    }
    g_is_mempool_loaded = !ShutdownRequested();
}
/** Sanity checks
 *  Ensure that Bitcoin is running in a usable environment with all
 *  necessary library support.
 */
static bool InitSanityCheck()
{
    if(!ECC_InitSanityCheck()) {
        InitError("Elliptic curve cryptography sanity check failure. Aborting.");
        return false;
    }
    if (!glibc_sanity_test() || !glibcxx_sanity_test())
        return false;
    if (!Random_SanityCheck()) {
        InitError("OS cryptographic RNG sanity check failure. Aborting.");
        return false;
    }
    return true;
}
static bool AppInitServers()