Remove the unused _api_version variable from volume tests

this variable was used to skip the v2 or v3 volume API test
based on below config options
    * ``CONF.volume-feature-enabled.api_v2``
    * ``CONF.volume-feature-enabled.api_v3``

Now those config options were deprecated and are going
to be removed from Tempest.

Volume tests run has been default to v3 and can be run against
v2 API via catalog_type config options. Any microversion
tests which cannot be run against v2 APIs will be skipped
by separate check of check_skip_with_microversion.

Change-Id: I6e05fbe21b29efa128fb59d16bf521d551b00304

tempest/api/volume/admin/test_group_snapshots.py

@@ -64,7 +64,6 @@ class BaseGroupSnapshotsTest(base.BaseVolumeAdminTest):
 class GroupSnapshotsTest(BaseGroupSnapshotsTest):
     """Test group snapshot"""
 
-    _api_version = 3
     min_microversion = '3.14'
     max_microversion = 'latest'
 
@@ -253,7 +252,6 @@ class GroupSnapshotsTest(BaseGroupSnapshotsTest):
 class GroupSnapshotsV319Test(BaseGroupSnapshotsTest):
     """Test group snapshot with volume microversion greater than 3.18"""
 
-    _api_version = 3
     min_microversion = '3.19'
     max_microversion = 'latest'
 

tempest/api/volume/admin/test_group_type_specs.py

@@ -21,7 +21,6 @@ from tempest.lib import exceptions as lib_exc
 class GroupTypeSpecsTest(base.BaseVolumeAdminTest):
     """Test group type specs"""
 
-    _api_version = 3
     min_microversion = '3.11'
     max_microversion = 'latest'
 

tempest/api/volume/admin/test_group_types.py

@@ -21,7 +21,6 @@ from tempest.lib import decorators
 class GroupTypesTest(base.BaseVolumeAdminTest):
     """Test group types"""
 
-    _api_version = 3
     min_microversion = '3.11'
     max_microversion = 'latest'
 

tempest/api/volume/admin/test_groups.py

@@ -25,7 +25,6 @@ CONF = config.CONF
 class GroupsTest(base.BaseVolumeAdminTest):
     """Tests of volume groups with microversion greater than 3.12"""
 
-    _api_version = 3
     min_microversion = '3.13'
     max_microversion = 'latest'
 
@@ -156,7 +155,6 @@ class GroupsTest(base.BaseVolumeAdminTest):
 class GroupsV314Test(base.BaseVolumeAdminTest):
     """Tests of volume groups with microversion greater than 3.13"""
 
-    _api_version = 3
     min_microversion = '3.14'
     max_microversion = 'latest'
 
@@ -194,7 +192,6 @@ class GroupsV314Test(base.BaseVolumeAdminTest):
 class GroupsV320Test(base.BaseVolumeAdminTest):
     """Tests of volume groups with microversion greater than 3.19"""
 
-    _api_version = 3
     min_microversion = '3.20'
     max_microversion = 'latest'
 

tempest/api/volume/admin/test_user_messages.py

@@ -24,7 +24,6 @@ CONF = config.CONF
 class UserMessagesTest(base.BaseVolumeAdminTest):
     """Test volume messages with microversion greater than 3.2"""
 
-    _api_version = 3
     min_microversion = '3.3'
     max_microversion = 'latest'
 

tempest/api/volume/base.py

@@ -32,7 +32,6 @@ class BaseVolumeTest(api_version_utils.BaseMicroversionTest,
     # Set this to True in subclasses to create a default network. See
     # https://bugs.launchpad.net/tempest/+bug/1844568
     create_default_network = False
-    _api_version = 2
     credentials = ['primary']
 
     @classmethod

tempest/api/volume/test_versions.py

@@ -19,8 +19,6 @@ from tempest.lib import decorators
 class VersionsTest(base.BaseVolumeTest):
     """Test volume versions"""
 
-    _api_version = 3
-
     @decorators.idempotent_id('77838fc4-b49b-4c64-9533-166762517369')
     @decorators.attr(type='smoke')
     def test_list_versions(self):

tempest/api/volume/test_volumes_backup.py

@@ -164,7 +164,6 @@ class VolumesBackupsTest(base.BaseVolumeTest):
 class VolumesBackupsV39Test(base.BaseVolumeTest):
     """Test volumes backup with volume microversion greater than 3.8"""
 
-    _api_version = 3
     min_microversion = '3.9'
     max_microversion = 'latest'
 

tempest/api/volume/test_volumes_extend.py

@@ -77,7 +77,6 @@ class BaseVolumesExtendAttachedTest(base.BaseVolumeTest):
     # details once that microversion is available in Nova.
     credentials = ['primary', 'admin']
 
-    _api_version = 3
     # NOTE(mriedem): The minimum required volume API version is 3.42 and the
     # minimum required compute API microversion is 2.51, but the compute call
     # is implicit - Cinder calls Nova at that microversion, Tempest does not.

tempest/api/volume/test_volumes_get.py

@@ -143,7 +143,6 @@ class VolumesGetTest(base.BaseVolumeTest):
 class VolumesSummaryTest(base.BaseVolumeTest):
     """Test volume summary"""
 
-    _api_version = 3
     min_microversion = '3.12'
     max_microversion = 'latest'