API change for verifying the scheduler when evacuating

Adding a new microversion for changing the evacuate action behaviour
to call the scheduler anyway unless the admin user provides a force
flag that then keeps the previous behaviour by forcing the conductor
to call the destination without verifying it.

Implements: blueprint check-destination-on-migrations

APIImpact

Change-Id: I9ecbe3d481bf17b12072511da4bb106ff1b6404e

nova/api/openstack/api_version_request.py

@@ -75,6 +75,8 @@ REST_API_VERSION_HISTORY = """REST API Version History:
     * 2.27 - Adds support for new-style microversion headers while
              keeping support for the original style.
     * 2.28 - Changes compute_node.cpu_info from string to object
+    * 2.29 - Add a force flag in evacuate request body and change the
+             behaviour for the host flag by calling the scheduler.
 """
 
 # The minimum and maximum versions of the API supported
@@ -83,7 +85,7 @@ REST_API_VERSION_HISTORY = """REST API Version History:
 # Note(cyeoh): This only applies for the v2.1 API once microversions
 # support is fully merged. It does not affect the V2 API.
 _MIN_API_VERSION = "2.1"
-_MAX_API_VERSION = "2.28"
+_MAX_API_VERSION = "2.29"
 DEFAULT_API_VERSION = _MIN_API_VERSION