upgrade eslint and update configuration for comma-dangle

Author: mojavelinux

.eslintrc

@@ -2,7 +2,12 @@
   "extends": "standard",
   "rules": {
     "arrow-parens": ["error", "always"],
-    "comma-dangle": ["error", "always-multiline"],
+    "comma-dangle": ["error", {
+      "arrays": "always-multiline",
+      "objects": "always-multiline",
+      "imports": "always-multiline",
+      "exports": "always-multiline"
+    }],
     "max-len": [1, 120, 2],
     "spaced-comment": "off"
   }

package-lock.json

@@ -19,7 +19,7 @@
     "browser-pack-flat": "~3.4",
     "browserify": "~16.5",
     "cssnano": "~4.1",
-    "eslint": "~6.5",
+    "eslint": "~6.6",
     "eslint-config-standard": "~14.1",
     "eslint-plugin-import": "~2.18",
     "eslint-plugin-node": "~10.0",