Don't use expect and jest-mock anymore as they're implicit from jest

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

test/components/views/messages/TextualBody-test.js

@@ -15,7 +15,6 @@ limitations under the License.
 */
 
 import React from "react";
-import expect from 'expect';
 import Adapter from "enzyme-adapter-react-16";
 import { configure, mount } from "enzyme";
 

test/components/views/rooms/RoomSettings-test.js

@@ -1,7 +1,6 @@
 // TODO: Rewrite room settings tests for dialog support
 import React from 'react';
 import ReactDOM from 'react-dom';
-import jest from 'jest-mock';
 import * as testUtils from '../../../test-utils';
 import sdk from '../../../skinned-sdk';
 import {MatrixClientPeg} from '../../../../src/MatrixClientPeg';