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 
"  \"headers\": xxxxxx,            (numeric) the current number of headers we have validated\n"
            "  \"bestblockhash\": \"...\",       (string) the hash of the currently best block\n"
            "  \"difficulty\": xxxxxx,         (numeric) the current difficulty\n"
            "  \"mediantime\": xxxxxx,         (numeric) median time for the current best block\n"
            "  \"verificationprogress\": xxxx, (numeric) estimate of verification progress [0..1]\n"
            "  \"initialblockdownload\": xxxx, (bool) (debug information) estimate of whether this node is in Initial Block Download mode.\n"
            "  \"chainwork\": \"xxxx\"           (string) total amount of work in active chain, in hexadecimal\n"
            "  \"size_on_disk\": xxxxxx,       (numeric) the estimated size of the block and undo files on disk\n"
            "  \"pruned\": xx,                 (boolean) if the blocks are subject to pruning\n"
            "  \"pruneheight\": xxxxxx,        (numeric) lowest-height complete block stored (only present if pruning is enabled)\n"
            "  \"automatic_pruning\": xx,      (boolean) whether automatic pruning is enabled (only present if pruning is enabled)\n"
            "  \"prune_target_size\": xxxxxx,  (numeric) the target size used by pruning (only present if automatic pruning is enabled)\n"
            "  \"softforks\": [                (array) status of softforks in progress\n"
            "     {\n"
            "        \"id\": \"xxxx\",           (string) name of softfork\n"
            "        \"version\": xx,          (numeric) block version\n"
            "        \"reject\": {             (object) progress toward rejecting pre-softfork blocks\n"
            "           \"status\": xx,        (boolean) true if threshold reached\n"
            "        },\n"
            "     }, ...\n"
            "  ],\n"
            "  \"bip9_softforks\": {           (object) status of BIP9 softforks in progress\n"
            "     \"xxxx\" : {                 (string) name of the softfork\n"
            "        \"status\": \"xxxx\",       (string) one of \"defined\", \"started\", \"locked_in\", \"active\", \"failed\"\n"
            "        \"bit\": xx,              (numeric) the bit (0-28) in the block version field used to signal this softfork (only for \"started\" status)\n"
            "        \"startTime\": xx,        (numeric) the minimum median time past of a block at which the bit gains its meaning\n"
            "        \"timeout\": xx,          (numeric) the median time past of a block at which the deployment is considered failed if not yet locked in\n"
            "        \"since\": xx,            (numeric) height of the first block to which the status applies\n"
            "        \"statistics\": {         (object) numeric statistics about BIP9 signalling for a softfork (only for \"started\" status)\n"
            "           \"period\": xx,        (numeric) the length in blocks of the BIP9 signalling period \n"