Migrate away from React.createClass for auth and views/auth. React 16 :D

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

src/components/structures/auth/Login.js

@@ -16,9 +16,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-'use strict';
-
 import React from 'react';
+import createReactClass from 'create-react-class';
 import PropTypes from 'prop-types';
 import {_t, _td} from '../../../languageHandler';
 import sdk from '../../../index';
@@ -54,7 +53,7 @@ _td("General failure");
 /**
  * A wire component which glues together login UI components and Login logic
  */
-module.exports = React.createClass({
+module.exports = createReactClass({
     displayName: 'Login',
 
     propTypes: {