Add Date Logical Type

- As a user of Woodwork, I wish I had a logical type to capture a list of date values (with no time).
- For example, to track when a user signed up for a gym membership
```
from datetime import date
dates = [
date(2010, 1, 1),
date(2010, 1, 15),
date(2010, 5, 1),
date(2010, 12, 12),
]
```