Remove CONF.volume_feature_enabled.bootable

The option is deprecated already and the os-set_bootable feature has
been implemented since Ib6cdca15950fe86b4fb2a43cfc7338e28260e453 .
That was 2.5 years ago. So we can remove this option.

Change-Id: I83085bc9e9747a5f427d1651408b265cc1e2030e
diff --git a/releasenotes/notes/remove-bootable-option-024f8944c056a3e0.yaml b/releasenotes/notes/remove-bootable-option-024f8944c056a3e0.yaml
new file mode 100644
index 0000000..e6e53af
--- /dev/null
+++ b/releasenotes/notes/remove-bootable-option-024f8944c056a3e0.yaml
@@ -0,0 +1,6 @@
+---
+deprecations:
+  - The *bootable* config option in the *volume_feature_enabled* group is
+    removed because the corresponding feature os-set_bootable has been
+    implemented 2.5 years ago and all OpenStack versions which are supported
+    by Tempest should support the feature.
diff --git a/tempest/api/volume/test_volumes_actions.py b/tempest/api/volume/test_volumes_actions.py
index 737ce5e..38f1082 100644
--- a/tempest/api/volume/test_volumes_actions.py
+++ b/tempest/api/volume/test_volumes_actions.py
@@ -12,7 +12,6 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
-import testtools
 
 from tempest.api.volume import base
 from tempest.common.utils import data_utils
@@ -67,8 +66,6 @@
                                        self.volume['id'], 'available')
 
     @test.idempotent_id('63e21b4c-0a0c-41f6-bfc3-7c2816815599')
-    @testtools.skipUnless(CONF.volume_feature_enabled.bootable,
-                          'Update bootable status of a volume is not enabled.')
     def test_volume_bootable(self):
         # Verify that a volume bootable flag is retrieved
         for bool_bootable in [True, False]:
diff --git a/tempest/config.py b/tempest/config.py
index bc9215c..a4527ed 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -780,11 +780,6 @@
     cfg.BoolOpt('api_v3',
                 default=False,
                 help="Is the v3 volume API enabled"),
-    cfg.BoolOpt('bootable',
-                default=True,
-                help='Update bootable status of a volume '
-                     'Not implemented on icehouse ',
-                deprecated_for_removal=True),
     # TODO(ynesenenko): Remove volume_services once liberty-eol happens.
     cfg.BoolOpt('volume_services',
                 default=False,