Add enumerated lists for API version and sovereign clouds

Author: samwelkanda

msgraphcore/enums.py

@@ -0,0 +1,17 @@
+from enum import Enum
+
+
+class APIVersion(str, Enum):
+    """Enumerated list of supported API Versions"""
+    beta = 'beta'
+    v1 = 'v1.0'
+
+
+class NationalClouds(str, Enum):
+    """Enumerated list of supported sovereign clouds"""
+
+    China = 'https://microsoftgraph.chinacloudapi.cn'
+    Germany = 'https://graph.microsoft.de'
+    Global = 'https://graph.microsoft.com'
+    US_DoD = 'https://dod-graph.microsoft.us'
+    US_GOV = 'https://graph.microsoft.us'