port test_images and test_server_actions into v3 part2

this ports test_images and server_action tests into v3 and
add a BaseComputeV3Test to avoid that nova v3 tests
call nova v2 url by mistake.

In nova v3 API there is no image API. So use glance
directly in test_images and change create_image to use
servers_client instead of images_client in BaseComputeTest,
as it's server's action.

Partially implements blueprint nova-v3-api-tests

Change-Id: I0371abbdce092d566c312ea73c563d817b37e226
diff --git a/etc/tempest.conf.sample b/etc/tempest.conf.sample
index 87bf758..4d02dc5 100644
--- a/etc/tempest.conf.sample
+++ b/etc/tempest.conf.sample
@@ -138,6 +138,11 @@
 # this value as "compute"
 catalog_type = compute
 
+# The type of endpoint for a Compute v3 API service. Unless you have a
+# custom Keystone service catalog implementation, you probably want to leave
+# this value as "computev3"
+catalog_v3_type = computev3
+
 # The name of a region for compute. If empty or commented-out, the value of
 # identity.region is used instead. If no such region is found in the service
 # catalog, the first found one is used.
@@ -147,6 +152,9 @@
 volume_device_name = vdb
 
 [compute-feature-enabled]
+# Do we run the Nova V3 API tests?
+api_v3 = true
+
 # Does the Compute API support creation of images?
 create_image = true