Remove the unused GroupsButton too

src/components/views/elements/GroupsButton.js

@@ -1,37 +0,0 @@
-/*
-Copyright 2017 New Vector Ltd
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-import React from 'react';
-import * as sdk from '../../../index';
-import PropTypes from 'prop-types';
-import { _t } from '../../../languageHandler';
-
-const GroupsButton = function(props) {
-    const ActionButton = sdk.getComponent('elements.ActionButton');
-    return (
-        <ActionButton className="mx_GroupsButton" action="toggle_my_groups"
-            label={_t("Communities")}
-            size={props.size}
-            tooltip={true}
-        />
-    );
-};
-
-GroupsButton.propTypes = {
-    size: PropTypes.string,
-};
-
-export default GroupsButton;