benchmark-lsp: fix ESLint parsing of edex-ui-filesystem.class.js

ESLint is failing to parse edex-ui-filesystem.class.js:

    [snip]/edex-ui-filesystem.class.js
      153:29  error  Parsing error: Unexpected token dir

    ✖ 1 problem (1 error, 0 warnings)

Fix parsing by telling ESLint to parse ECMAscript version 2017, which
has support for async/await.

Author: strager

benchmark/benchmark-lsp/eslint/.eslintrc.json

@@ -4,6 +4,9 @@
         "es6": true,
         "node": true
     },
+    "parserOptions": {
+        "ecmaVersion": 2017
+    },
     "extends": "eslint:recommended",
     "rules": {
       "no-unused-vars": ["error", {