Upgrade eslint & commander (out of current ranges) (#525)

* Upgrade eslint-config-airbnb-base to ^14.0.0

* Upgrade eslint to ^6.7.2

* Upgrade commander to ^4.0.1

Author: Throne3d

.eslintrc

@@ -6,6 +6,7 @@
     "node": true
   },
   "rules": {
+    "arrow-parens": 0,
     "global-require": 0,
     "comma-dangle": 0,
     "func-names": 0,

lib/logger.js

@@ -3,11 +3,12 @@ import { inspect } from 'util';
 
 function formatter(info) {
   const stringifiedRest = inspect(
-    Object.assign({}, info, {
+    {
+      ...info,
       level: undefined,
       message: undefined,
       splat: undefined
-    }),
+    },
     { depth: null }
   );