Disable velocity mock option

This appears to have been removed in the beta

test/components/structures/MessagePanel-test.js

@@ -35,7 +35,6 @@ const mockclock = require('../../mock-clock');
 import Adapter from "enzyme-adapter-react-16";
 import { configure, mount } from "enzyme";
 
-import Velocity from 'velocity-animate';
 import MatrixClientContext from "../../../src/contexts/MatrixClientContext";
 import RoomContext from "../../../src/contexts/RoomContext";
 import DMRoomMap from "../../../src/utils/DMRoomMap";
@@ -75,18 +74,10 @@ describe('MessagePanel', function() {
             return arg === "showDisplaynameChanges";
         });
 
-        // This option clobbers the duration of all animations to be 1ms
-        // which makes unit testing a lot simpler (the animation doesn't
-        // complete without this even if we mock the clock and tick it
-        // what should be the correct amount of time).
-        Velocity.mock = true;
-
         DMRoomMap.makeShared();
     });
 
     afterEach(function() {
-        delete Velocity.mock;
-
         clock.uninstall();
     });