[WIP] force es5 in linter

Author: fanatid

package.json

@@ -32,11 +32,25 @@
     "buffer": false
   },
   "devDependencies": {
+    "eslint-plugin-es5": "^1.4.1",
     "mocha": "^6.1.4",
     "standardx": "^4.0.0"
   },
   "eslintConfig": {
+    "plugins": [
+      "es5"
+    ],
+    "extends": [
+      "plugin:es5/no-es2015"
+    ],
+    "parserOptions": {
+      "ecmaVersion": 2015
+    },
+    "env": {
+      "es6": false
+    },
     "rules": {
+      "es5/no-es6-static-methods": ["error", { "exceptMethods": ["Math.imul"] }],
       "semi": [
         2,
         "always"

yarn.lock

@@ -344,6 +344,11 @@ eslint-module-utils@^2.4.0:
     debug "^2.6.8"
     pkg-dir "^2.0.0"
 
+eslint-plugin-es5@^1.4.1:
+  version "1.4.1"
+  resolved "https://registry.yarnpkg.com/eslint-plugin-es5/-/eslint-plugin-es5-1.4.1.tgz#258fe89bc5f72fbd9f5f7936c840151766821f1e"
+  integrity sha512-kktkmkF2O7pnSZYgrMiYMbt3wCKRIiXePwILv8USDG95YgP0PzhIxSIROLLKmiQQ/Z6LuhDGWTHK04gnbXBvkg==
+
 eslint-plugin-es@^1.4.0:
   version "1.4.0"
   resolved "https://registry.yarnpkg.com/eslint-plugin-es/-/eslint-plugin-es-1.4.0.tgz#475f65bb20c993fc10e8c8fe77d1d60068072da6"