Time picker does not render for local time formats (LT, LTS)

### I'm Submitting a ...

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

### Steps to Reproduce

1. Go to https://youcanbookme.github.io/react-datetime/
2. Change `timeFormat` to LT or LTS
3. Click on the picker, then click on the time label at the bottom of the pop-out

### Expected Results
The time picker appears, with hours and minutes for LT and hours, minutes, seconds for LTS

### Actual Results
Nothing appears