message: fix(withLatestFrom): change from hot to cold observable in marble test
  fixes
diff: @@ -14,8 +14,8 @@ const Observable = Rx.Observable;
  /** @test {withLatestFrom} */
  describe('Observable.prototype.withLatestFrom', () => {
  asDiagram('withLatestFrom')('should combine events from cold observables', () => {
  - const e1 = hot('-a--b-----c-d-e-|');
  - const e2 = hot('--1--2-3-4---| ');
  + const e1 = cold('-a--b-----c-d-e-|');
  + const e2 = cold('--1--2-3-4---| ');
  const expected = '----B-----C-D-E-|';
  const result = e1.withLatestFrom(e2, (a: string, b: string) => String(a) + String(b));
  