Implement the warehouse create, update and delete endpoints

[livingforjesus]

Create Warehouse - https://www.shipstation.com/docs/api/warehouses/create/ Update Warehouse - https://www.shipstation.com/docs/api/warehouses/update/ Delete Warehouse - https://www.shipstation.com/docs/api/warehouses/delete/

• Implement the create, update and delete warehouse endpoints
• The docs says that warehouseName is optional, however while testing it with my store, it was required