fix: Add missing fields to IPv6Range (#318)

## 📝 Description

[IPv6 range
view](https://www.linode.com/docs/api/networking/#ipv6-range-view__responses)
and [IPv6 range
list](https://www.linode.com/docs/api/networking/#ipv6-ranges-list__responses)
actually share different response structures. The current `IPv6Range`
object has been built based on the structure of IPv6 range list, so
fields `linodes` and `is_bgp` are missing. To quickly fix it, I think
simply adding these two fields to the `IPv6Range` object properties
makes sense without introducing any breaking change. Otherwise we may
consider create two separated objects for returning a single object and
list, which is probably confusing for customers to use and more
complicated for us to maintain. Any different idea is appreciated.

## ✔️ How to Test

`tox`

Author: yec-akamai

linode_api4/objects/networking.py

@@ -31,6 +31,8 @@ class IPv6Range(Base):
         "region": Property(slug_relationship=Region),
         "prefix": Property(),
         "route_target": Property(),
+        "linodes": Property(),
+        "is_bgp": Property(),
     }
 
 

test/unit/objects/networking_test.py

@@ -20,6 +20,8 @@ def test_get_ipv6_range(self):
         self.assertEqual(ipv6Range.range, "2600:3c01::")
         self.assertEqual(ipv6Range.prefix, 64)
         self.assertEqual(ipv6Range.region.id, "us-east")
+        self.assertEqual(ipv6Range.linodes[0], 123)
+        self.assertEqual(ipv6Range.is_bgp, False)
 
         ranges = self.client.networking.ipv6_ranges()