Remove unused import
Allow Person to be serialized
Add constructors to EMailAddress
Make phoneNumbers and emailAddresses not required in ContactData
Introduce destroyEntity
Introduce createEntity with any object
Support creation of tags (a bit special operation as the highrise api doesn't like a "tag" root element to be present in the post)
Refactor tests so that no known entities needs to be present in highrise. A test person is created and destroyed during the execution.