Abstract menu animation

client/source/scripts/components/forms/Dropdown.js

@@ -137,7 +137,7 @@ export default class Dropdown extends React.Component {
       <div className={dropdownWrapperClass} onFocus={this.handleDropdownFocus} onBlur={this.handleDropdownBlur} ref="dropdown" tabIndex="0">
         {this.getDropdownButton()}
         <CSSTransitionGroup
-          transitionName="dropdown__content"
+          transitionName="menu"
           transitionEnterTimeout={250}
           transitionLeaveTimeout={250}>
           {menu}

client/source/scripts/components/torrent-list/TorrentList.js

@@ -322,7 +322,12 @@ export default class TorrentListContainer extends React.Component {
 
       content = (
         <ul className="torrent__list" key="torrent__list">
-          {contextMenu}
+          <CSSTransitionGroup
+            transitionName="menu"
+            transitionEnterTimeout={250}
+            transitionLeaveTimeout={250}>
+            {contextMenu}
+          </CSSTransitionGroup>
           <li className="torrent__spacer torrent__spacer--top"
             style={{height: `${listPadding.top}px`}}></li>
           {torrentList}

client/source/scripts/components/ui/ContextMenu.js

@@ -1,5 +1,4 @@
 import classnames from 'classnames';
-import CSSTransitionGroup from 'react-addons-css-transition-group';
 import React from 'react';
 import ReactDOM from 'react-dom';