Add eslint rule to require parentheses in arrow functions

[MAILPOET-2162]

assets/js/src/help/tasks_list/tasks_list.jsx

@@ -12,7 +12,7 @@ const TasksList = (props) => {
       <thead><TaskListLabelsRow show_scheduled_at={props.show_scheduled_at} /></thead>
       <tbody>
         {
-          props.tasks.length ? props.tasks.map(task => (
+          props.tasks.length ? props.tasks.map((task) => (
             <TaskListDataRow
               key={task.id}
               task={task}

assets/js/src/help/tasks_list/tasks_list_data_row.jsx

@@ -2,7 +2,7 @@ import PropTypes from 'prop-types';
 import React from 'react';
 import MailPoet from 'mailpoet';
 
-const TasksListDataRow = props => (
+const TasksListDataRow = (props) => (
   <tr>
     <td className="column column-primary">
       { props.task.id }

assets/js/src/help/tasks_list/tasks_list_labels_row.jsx

@@ -2,7 +2,7 @@ import PropTypes from 'prop-types';
 import React from 'react';
 import MailPoet from 'mailpoet';
 
-const TasksListLabelsRow = props => (
+const TasksListLabelsRow = (props) => (
   <tr>
     <th className="row-title">Id</th>
     <th className="row-title">{MailPoet.I18n.t('type')}</th>