Add constants for room versions

synapse/api/constants.py

@@ -97,9 +97,14 @@ class ThirdPartyEntityKind(object):
     LOCATION = "location"
 
 
+class RoomVersions(object):
+    V1 = "1"
+    VDH_TEST = "vdh-test-version"
+
+
 # the version we will give rooms which are created on this server
-DEFAULT_ROOM_VERSION = "1"
+DEFAULT_ROOM_VERSION = RoomVersions.V1
 
 # vdh-test-version is a placeholder to get room versioning support working and tested
 # until we have a working v2.
-KNOWN_ROOM_VERSIONS = {"1", "vdh-test-version"}
+KNOWN_ROOM_VERSIONS = {RoomVersions.V1, RoomVersions.VDH_TEST}