Time Picker disappears right after I click arrows to update time

[ x] Bug report
[ ] Feature request
[ ] Support request
```

### Steps to Reproduce
react: 16.2.0
react-datetime: 2.15.0
react-treebeard: 2.1.0

```

```

### Expected Results

Time picker should not disappear that user can go back to Date picker

### Actual Results

Year picker, month picker, date picker works well, but only time picker disappears right after I click arrows