SDK-1031: Use UNKNOWN_ANCHOR_TYPE for initialization of anchor

Co-Authored-By: Ed Harrod <echarrod@users.noreply.github.com>

Author: emmas-yoti

yoti_python_sdk/anchor.py

@@ -19,7 +19,7 @@
 class Anchor:
     def __init__(
         self,
-        anchor_type="Unknown",
+        anchor_type=UNKNOWN_ANCHOR_TYPE,
         sub_type="",
         value="",
         signed_timestamp=None,

yoti_python_sdk/client.py

@@ -100,7 +100,6 @@ def perform_aml_check(self, aml_profile):
         return aml.AmlResult(response.text)
 
     def make_request(self, http_method, endpoint, body):
-
         url = yoti_python_sdk.YOTI_API_ENDPOINT + endpoint
         headers = self.__get_request_headers(endpoint, http_method, body)
         response = requests.request(http_method, url, headers=headers, data=body, verify=yoti_python_sdk.YOTI_API_VERIFY_SSL)