Add configuration support for skipping tests

This patch add configuration support in Octavia Tempest Plugin,
in case a provider driver does not support Health Monitors.

Change-Id: I25eb52e9f64a08560c9ea2f664edd9826be6e379
diff --git a/octavia_tempest_plugin/config.py b/octavia_tempest_plugin/config.py
index b683ee3..62affc0 100644
--- a/octavia_tempest_plugin/config.py
+++ b/octavia_tempest_plugin/config.py
@@ -144,3 +144,12 @@
                default=None,
                help='Availability zone to use for creating servers.'),
 ]
+
+lb_feature_enabled_group = cfg.OptGroup(name='loadbalancer-feature-enabled',
+                                        title='Enabled/Disabled LB features')
+LBFeatureEnabledGroup = [
+    cfg.BoolOpt('health_monitor_enabled',
+                default=True,
+                help="Whether Health Monitor is available with provider"
+                     " driver or not."),
+]