chore: require at least node 8 (#16)

* chore: support node 12 and requires at least node 8

* chore: ignore nyc logs and package-lock

* feat: support ES2018

* Revert "feat: support ES2018"

This reverts commit 0ea47cc.

* fix: don't specify ecmaversion

* eslint-plugin-node@9 adds ecmaversion 2019 by default
* https://github.com/mysticatea/eslint-plugin-node/tree/v9.0.0#-configs

.gitignore

@@ -3,4 +3,5 @@ node_modules/
 tmp/
 *.log
 .idea/
-coverage/
+.nyc_output/
+package-lock.json

eslint.js

@@ -129,8 +129,5 @@ module.exports = {
   env: {
     node: true,
     es6: true
-  },
-  parserOptions: {
-    ecmaVersion: 6
   }
 };

package.json

@@ -15,9 +15,12 @@
   ],
   "license": "MIT",
   "peerDependencies": {
-    "eslint": ">= 3.1.0"
+    "eslint": ">= 5.0.0"
   },
   "dependencies": {
-    "eslint-plugin-node": "^5.2.1"
+    "eslint-plugin-node": "^9.1.0"
+  },
+  "engines": {
+    "node": ">=8.6.0"
   }
 }