message: put maySendMessage stub on stubRoom in the right place
diff: @@ -247,12 +247,12 @@ export function mkStubRoom(roomId = null) {
  getVersion: () => '1',
  shouldUpgradeToVersion: () => null,
  getMyMembership: () => "join",
  + maySendMessage: sinon.stub().returns(true),
  currentState: {
  getStateEvents: sinon.stub(),
  mayClientSendStateEvent: sinon.stub().returns(true),
  maySendStateEvent: sinon.stub().returns(true),
  maySendEvent: sinon.stub().returns(true),
  - maySendMessage: sinon.stub().returns(true),
  members: [],
  },
  tags: {
  