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 
void UpdateEntryForAncestors(txiter it, const setEntries &setAncestors) EXCLUSIVE_LOCKS_REQUIRED(cs);
    /** For each transaction being removed, update ancestors and any direct children.
      * If updateDescendants is true, then also update in-mempool descendants'
      * ancestor state. */
    void UpdateForRemoveFromMempool(const setEntries &entriesToRemove, bool updateDescendants) EXCLUSIVE_LOCKS_REQUIRED(cs);
    
    void UpdateChildrenForRemoval(txiter entry) EXCLUSIVE_LOCKS_REQUIRED(cs);
    /** Before calling removeUnchecked for a given transaction,
     *  UpdateForRemoveFromMempool must be called on the entire (dependent) set
     *  of transactions being removed at the same time.  We use each
     *  CTxMemPoolEntry's setMemPoolParents in order to walk ancestors of a
     *  given transaction that is removed, so we can't remove intermediate
     *  transactions in a chain before we've updated all the state for the
     *  removal.
     */
    void removeUnchecked(txiter entry, MemPoolRemovalReason reason = MemPoolRemovalReason::UNKNOWN) EXCLUSIVE_LOCKS_REQUIRED(cs);
};
/**
 * CCoinsView that brings transactions from a mempool into view.
 * It does not check for spendings by memory pool transactions.
 * Instead, it provides access to all Coins which are either unspent in the
 * base CCoinsView, or are outputs from any mempool transaction!
 * This allows transaction replacement to work as expected, as you want to
 * have all inputs "available" to check signatures, and any cycles in the
 * dependency graph are checked directly in AcceptToMemoryPool.
 * It also allows you to sign a double-spend directly in
 * signrawtransactionwithkey and signrawtransactionwithwallet,
 * as long as the conflicting transaction is not yet confirmed.
 */
class CCoinsViewMemPool : public CCoinsViewBacked