Add Collapse component (#3867)

client/app/assets/less/ant.less

@@ -33,6 +33,7 @@
 @import "~antd/lib/spin/style/index";
 @import "~antd/lib/tabs/style/index";
 @import "~antd/lib/notification/style/index";
+@import "~antd/lib/collapse/style/index";
 @import "~antd/lib/progress/style/index";
 @import 'inc/ant-variables';
 
@@ -322,3 +323,25 @@
 .@{btn-prefix-cls} .@{iconfont-css-prefix}-ellipsis {
   margin: 0 -7px;
 }
+
+// Collapse
+
+.@{collapse-prefix-cls} {
+  &&-headerless {
+    border: 0;
+    background: none;
+
+    .@{collapse-prefix-cls}-header {
+      display: none;
+    }
+
+    .@{collapse-prefix-cls}-item,
+    .@{collapse-prefix-cls}-content {
+      border: 0;
+    }
+
+    .@{collapse-prefix-cls}-content-box {
+      padding: 0;
+    }
+  }
+}

client/app/components/Collapse.jsx

@@ -0,0 +1,24 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import cx from 'classnames';
+import AntCollapse from 'antd/lib/collapse';
+
+export default function Collapse({ collapsed, children, className, ...props }) {
+  return (
+    <AntCollapse {...props} activeKey={collapsed ? null : 'content'} className={cx(className, 'ant-collapse-headerless')}>
+      <AntCollapse.Panel key="content" header="">{children}</AntCollapse.Panel>
+    </AntCollapse>
+  );
+}
+
+Collapse.propTypes = {
+  collapsed: PropTypes.bool,
+  children: PropTypes.node,
+  className: PropTypes.string,
+};
+
+Collapse.defaultProps = {
+  collapsed: true,
+  children: null,
+  className: '',
+};