Add standalone tests using direct HTTP links

Adds two tests that uses direct HTTP link instead of glance:
  * pxe_ipmitool + wholedisk on HTTP server
  * agent_ipmitool + wholedisk on HTTP server

Change-Id: I8f1a5b0ecb3d53ffdefd7018c1b9700210572ffc
diff --git a/ironic_tempest_plugin/plugin.py b/ironic_tempest_plugin/plugin.py
index dbe0f0b..9e9c175 100644
--- a/ironic_tempest_plugin/plugin.py
+++ b/ironic_tempest_plugin/plugin.py
@@ -21,6 +21,12 @@
 
 from ironic_tempest_plugin import config as project_config
 
+_opts = [
+    (project_config.baremetal_group, project_config.BaremetalGroup),
+    (project_config.baremetal_features_group,
+     project_config.BaremetalFeaturesGroup)
+]
+
 
 class IronicTempestPlugin(plugins.TempestPlugin):
     def load_tests(self):
@@ -33,9 +39,8 @@
     def register_opts(self, conf):
         conf.register_opt(project_config.service_option,
                           group='service_available')
-        config.register_opt_group(conf, project_config.baremetal_group,
-                                  project_config.BaremetalGroup)
+        for group, option in _opts:
+            config.register_opt_group(conf, group, option)
 
     def get_opt_lists(self):
-        return [(project_config.baremetal_group.name,
-                 project_config.BaremetalGroup)]
+        return [(group.name, option) for group, option in _opts]