Merge pull request #168 from ethereumjs/update-winston

Update winston to v3.3.3

Author: holgerd77

package.json

@@ -81,7 +81,7 @@
     "qheap": "^1.4.0",
     "rlp": "^2.0.0",
     "util-promisify": "^2.1.0",
-    "winston": "^3.1.0",
+    "winston": "3.3.3",
     "yargs": "^13.2.1"
   },
   "devDependencies": {