SPHERE-1212 add new commands on Customer

3 new commands to update the customer.
- setCompanyName
- setVatId
- setDateOfBirth

For the last command I had to add a new Jackson serializer for the LocalDate type.
Please never return null.

```
public Optional<String> getCompanyName() { return Optional.fromNullable(companyName); }
public Optional<String> getVatId() {... }
public Optional<LocalDate> getDateOfBirth() { . }
```