message: modify dcn.json to show AUC and model dump
diff: "solver": {
  "lr_policy": "fixed",
  "display": 1000,
  - "max_iter": 10000,
  + "max_iter": 71000,
  "gpu": [0,1,2,3],
  "batchsize": 512,
  - "snapshot": 10000000,
  + "snapshot": 70999,
  "snapshot_prefix": "./",
  - "eval_interval": 1000,
  - "eval_batches": 60
  + "eval_interval": 2000,
  + "eval_batches": 8000
  },
  "optimizer": {
  