Migrate away from React.createClass for non-auth structures. React 16 :D

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/components/structures/LoggedInView.js

@@ -18,6 +18,7 @@ limitations under the License.
 
 import { MatrixClient } from 'matrix-js-sdk';
 import React from 'react';
+import createReactClass from 'create-react-class';
 import PropTypes from 'prop-types';
 import { DragDropContext } from 'react-beautiful-dnd';
 
@@ -58,7 +59,7 @@ function canElementReceiveInput(el) {
  *
  * Components mounted below us can access the matrix client via the react context.
  */
-const LoggedInView = React.createClass({
+const LoggedInView = createReactClass({
     displayName: 'LoggedInView',
 
     propTypes: {