Change eslint rule arrow-parens to always

Author: tshemsedinov

.eslintrc.json

@@ -208,7 +208,7 @@
     ],
     "arrow-parens": [
       "error",
-      "as-needed"
+      "always"
     ],
     "arrow-body-style": [
       "error",

JavaScript/4-concat.js

@@ -26,7 +26,7 @@ for (const key in hash1) {
 console.dir({ keys: Object.keys(hash1) });
 console.dir({ hash1 });
 
-const save = collection => fs.writeFile(
+const save = (collection) => fs.writeFile(
   collection[SYMBOL_FILENAME], v8.serialize(collection), () => {}
 );