fixing eslint errors

web/react/components/mention.jsx

@@ -1,6 +1,7 @@
 // Copyright (c) 2015 Mattermost, Inc. All Rights Reserved.
 // See License.txt for license information.
 var UserStore = require('../stores/user_store.jsx');
+const Utils = require('../utils/utils.jsx');
 
 export default class Mention extends React.Component {
     constructor(props) {

web/react/components/search_results_item.jsx

@@ -77,7 +77,7 @@ export default class SearchResultsItem extends React.Component {
                 <div className='post-profile-img__container'>
                     <img
                         className='post-profile-img'
-                        src={'/api/v1/users/' + this.props.post.user_id + '/image?time=' + timestamp + '&' + Utils.getSessionIndex()}
+                        src={'/api/v1/users/' + this.props.post.user_id + '/image?time=' + timestamp + '&' + utils.getSessionIndex()}
                         height='36'
                         width='36'
                     />

web/react/components/sidebar_header.jsx

@@ -3,6 +3,7 @@
 
 var NavbarDropdown = require('./navbar_dropdown.jsx');
 var UserStore = require('../stores/user_store.jsx');
+const Utils = require('../utils/utils.jsx');
 
 export default class SidebarHeader extends React.Component {
     constructor(props) {