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.
@butenkor You are right. 
We have created an issue internally to add those fields to the CreateCustomer backend API and propagate the changes to the SDKs in order to minimize API calls.