is_event should do something now; more updates coming

contributors should be a list of dictionaries not a list of strings.
`['']` is a list with a single empty string in it

And as noted below `is` is an identity comparison, so:
```python
['test'] is ['test']  # False
['test'] == ['test']  # True
```

Here is another place where using `if normalized['contributors'] would be preferable as an empty list, `[]` is also falsey

```python
def is_empty_list(list):
    if list:
       return True
    return False

is_empty_list([])  # True
is_empy_list([''])  # False
```