lint: apply standard 13 style

Author: dougwilson

.travis.yml

@@ -63,7 +63,7 @@ before_install:
     fi
   - |
     # Configure eslint for linting
-    if node_version_lt '6.0'; then npm_remove_module_re '^eslint(-|$)'
+    if node_version_lt '8.0'; then npm_remove_module_re '^eslint(-|$)'
     fi
   - |
     # Configure mocha for testing

package.json

@@ -19,8 +19,8 @@
   },
   "devDependencies": {
     "after": "0.8.2",
-    "eslint": "5.16.0",
-    "eslint-config-standard": "12.0.0",
+    "eslint": "6.1.0",
+    "eslint-config-standard": "13.0.1",
     "eslint-plugin-import": "2.18.2",
     "eslint-plugin-markdown": "1.0.0",
     "eslint-plugin-node": "8.0.1",