Merge branch 'bugfix/firma-model' into 'master'

Adjust Firma models

See merge request !56

ubw_client/models.py

@@ -533,13 +533,13 @@ class Firma(BaseModel):
     tax_office_reference: str
     tax_system: str
     vat_registration_number: str
-    multi_company_information: Connection
-    accounting: Accounts
-    currency_information: Currency
-    vat_information: VAT
+    multi_company_information: typing.Optional[Connection]
+    accounting: typing.Optional[Accounts]
+    currency_information: typing.Optional[Currency]
+    vat_information: typing.Optional[VAT]
     last_updated: UpdatedInfo
-    contact_points: typing.List[ContactPoint]
-    related_values: typing.List[RelatedValue]
+    contact_points: typing.Optional[typing.List[ContactPoint]]
+    related_values: typing.Optional[typing.List[RelatedValue]]
 
     class Config:
         alias_generator = to_lower_camel