initial fixing

Signed-off-by: Jess Frazelle <github@jessfraz.com>

kittycad/models/invoice_status.py

@@ -0,0 +1,13 @@
+from enum import Enum
+
+
+class InvoiceStatus(str, Enum):
+    DELETED = 'deleted'
+    DRAFT = 'draft'
+    OPEN = 'open'
+    PAID = 'paid'
+    UNCOLLECTIBLE = 'uncollectible'
+    VOID = 'void'
+
+    def __str__(self) -> str:
+        return str(self.value)