[Bug] Quick Trip Layer Formatting Crash Question

**Describe the bug**
Crashes when I try and load trip information that has been formatted.

**To Reproduce**
Using Jupyter, everything works except for the Trip layer. Here's an example of my data node:
`Hi, I keep getting the same problem too, and I spent the last 5 hours trying to figure out why it's crashing. Here's an example snippet:

```
{'type': 'FeatureCollection',
'features': [{'type': 'Feature',
'geometry': {'coordinates': [[-75.19078859999998,
39.9527732,
0,
1449704491271],
[-75.190796, 39.95274, 0, 1449704521285.0],
[-75.190796, 39.95274, 0, 1449704491271.0],
[-75.19078859999998, 39.9527732, 0, 1449704521285.0]],
'type': 'LineString'},
'properties': {'distance': 1, 'duration': 0}}]}
```
Is there anything wrong with the format structure above? This is driving me crazy, and I read the docs multiple times. Love Kepler though; appreciate all the work you've put into it.`

**Expected behavior**
Trip layer to animate / not crash. I can't tell what I'm doing wrong since it looks like I'm following the docs correctly.

Start with the supplied FeatureCollection and the Jupyter Trip layer entry point, then compare its geometry and timestamp structure with the documented format. Reproduce the crash using the example data and determine whether the input is accepted; done means the Trip layer animates without crashing or the issue clearly identifies the invalid field.

Written by the indexing model from the issue text.