Fix prefer-spread issues (#9203)

See [`prefer-spread`](https://eslint.org/docs/rules/prefer-spread) for more information.

This change enables `prefer-spread` and fixes the issues raised by the rule.

.eslintrc.js

@@ -54,6 +54,7 @@ module.exports = {
     'no-plusplus': ['error', { 'allowForLoopAfterthoughts': true }],
     'no-useless-catch': 'error',
     'no-useless-concat': 'error',
+    'prefer-spread': 'error',
     /* End v2 rules */
     'arrow-parens': 'error',
     'no-tabs': 'error',

app/scripts/account-import-strategies/index.js

@@ -8,7 +8,7 @@ const accountImporter = {
   importAccount (strategy, args) {
     try {
       const importer = this.strategies[strategy]
-      const privateKeyHex = importer.apply(null, args)
+      const privateKeyHex = importer(...args)
       return Promise.resolve(privateKeyHex)
     } catch (e) {
       return Promise.reject(e)