Thomas Lallement f2c75ebc9d
Fix Open API doc for DateTime requirements
When using the following requierement:

```
@Rest\QueryParam(name="updatedFrom", strict=true, nullable=true, requirements=@Constraints\DateTime("Y-m-d\TH:i:s"))
```

According to the OpenAPI 3.0 documentation https://swagger.io/specification/, we should have "format": "date-time" rather than "format": "DateTime" in the generated doc
2021-03-11 19:06:17 +01:00
..
2020-05-28 13:19:11 +02:00
2020-09-20 20:38:43 +02:00