Add function descriptions for tempest plugin

Change-Id: Id6791a3df84d474c95b6b043c90180d09d4d824f
diff --git a/heat_tempest_plugin/plugin.py b/heat_tempest_plugin/plugin.py
index 6926691..0eeb519 100644
--- a/heat_tempest_plugin/plugin.py
+++ b/heat_tempest_plugin/plugin.py
@@ -22,7 +22,23 @@
 
 
 class HeatTempestPlugin(plugins.TempestPlugin):
+    """A HeatTempestPlugin class
+
+    Provides the basic hooks for an external plugin to provide tempest the
+    necessary information to run the plugin.
+    """
+
     def load_tests(self):
+        """Provide Load tests information
+
+        Method to return the information necessary to load the tests in the
+        plugin.
+
+        :return: a tuple with the first value being the test_dir and the second
+                 being the top_level
+        :return type: tuple
+        """
+
         base_path = os.path.split(os.path.dirname(
             os.path.abspath(__file__)))[0]
         test_dir = "heat_tempest_plugin"
@@ -30,6 +46,15 @@
         return full_test_dir, base_path
 
     def register_opts(self, conf):
+        """Add additional configuration options to tempest.
+
+        This method will be run for the plugin during the register_opts()
+        function in tempest.config
+
+        Parameters:
+        conf (ConfigOpts): The conf object that can be used to register
+        additional options on.
+        """
         config.register_opt_group(conf, heat_config.service_available_group,
                                   heat_config.ServiceAvailableGroup)
         config.register_opt_group(conf, heat_config.heat_group,
@@ -38,6 +63,13 @@
                                   heat_config.HeatFeaturesGroup)
 
     def get_opt_lists(self):
+        """Get a list of options for sample config generation
+
+        Return option_list: A list of tuples with the group name
+                            and options in that group.
+        Return type: list
+        """
+
         return [(heat_config.heat_group.name,
                  heat_config.HeatGroup),
                 (heat_config.heat_features_group.name,