update eslintrc

Author: NessunKim

tests/.eslintrc

@@ -1,6 +1,6 @@
 {
   "parserOptions": {
-    "ecmaVersion": 8,
+    "ecmaVersion": 9,
     "sourceType": "script"
   },
   "env": {
@@ -10,35 +10,35 @@
   },
   "rules": {
     "no-unused-vars": [2, {
-      "argsIgnorePattern": "req|res|next|err",
+      "argsIgnorePattern": "req|res|next|err"
     }],
     "no-param-reassign": [0],
     "no-restricted-syntax": [
       "error",
       {
         "selector": "ForInStatement",
-        "message": "for..in loops iterate over the entire prototype chain, which is virtually never what you want. Use Object.{keys,values,entries}, and iterate over the resulting array.",
+        "message": "for..in loops iterate over the entire prototype chain, which is virtually never what you want. Use Object.{keys,values,entries}, and iterate over the resulting array."
       },
       {
         "selector": "LabeledStatement",
-        "message": "Labels are a form of GOTO; using them makes code confusing and hard to maintain and understand.",
+        "message": "Labels are a form of GOTO; using them makes code confusing and hard to maintain and understand."
       },
       {
         "selector": "WithStatement",
-        "message": "`with` is disallowed in strict mode because it makes code impossible to predict and optimize.",
-      },
+        "message": "`with` is disallowed in strict mode because it makes code impossible to predict and optimize."
+      }
     ],
     "comma-dangle": ["error", {
       "arrays": "always-multiline",
       "objects": "always-multiline",
       "imports": "always-multiline",
       "exports": "always-multiline",
-      "functions": "never",
+      "functions": "never"
     }],
     "no-console": [0],
     "no-await-in-loop": [0],
     "no-shadow": [0],
-    "import/no-extraneous-dependencies": ['error', {"devDependencies": true }],
+    "import/no-extraneous-dependencies": ["error", {"devDependencies": true }],
     "no-unused-expressions": [0]
   },
   "extends": "airbnb-base"