Tempest: wrap instance actions into inspector methods

This commit I4fe31ecae3393abc2779a5e80e348899f9113f1b broke inspector
tempest tests, it changes boot_instance and terminate_instance
signature.

This change redefine action methods

Change-Id: If6a9b300bd22e7b62b7e53763cb0328ad30f11c7
diff --git a/ironic_tempest_plugin/tests/test_basic.py b/ironic_tempest_plugin/tests/test_basic.py
index 6830b78..0e11cf5 100644
--- a/ironic_tempest_plugin/tests/test_basic.py
+++ b/ironic_tempest_plugin/tests/test_basic.py
@@ -145,5 +145,5 @@
 
         self.wait_for_nova_aware_of_bvms()
         self.add_keypair()
-        self.boot_instance()
-        self.terminate_instance()
+        ins, _node = self.boot_instance()
+        self.terminate_instance(ins)