Add a per-test log

This patch adds a new per-test logging feature to Patrole
To accomplish this, it adds two new config variables

The logging now prints a log message containing the results of each RBAC
test to a separate log file, as well as to the normal
tempest.log file. This message is of the form:
[Service] <nova, neutron, etc>
[Test] <name of the test's method>
followed by either the result of the test as Allowed/Denied/Error, or
the expected result (from oslopolicy) and then the actual result

There are two new config variables that control this, added in a new
config group called patrole_log:
enable_reporting - defaults to True, which enables this new logging
functionality
report_log_name - defaults to patrole.log, controls the name of the log
the output is written to.
report_log_path - Defaults to the local directory, path (relative or
absolute) where to store the log

Change-Id: Iff2176f1a7c7d10f78b96d748f1d70b222fd5072
diff --git a/patrole_tempest_plugin/config.py b/patrole_tempest_plugin/config.py
index a53edd4..fcf29af 100644
--- a/patrole_tempest_plugin/config.py
+++ b/patrole_tempest_plugin/config.py
@@ -147,3 +147,23 @@
                           help="This group is deprecated and will be removed "
                                "in the next release. Use the [patrole] group "
                                "instead.")
+
+patrole_log_group = cfg.OptGroup(
+    name='patrole_log', title='Patrole Logging Options')
+
+PatroleLogGroup = [
+    cfg.BoolOpt('enable_reporting',
+                default=False,
+                help="Enables reporting on RBAC expected and actual test "
+                     "results for each Patrole test"),
+    cfg.StrOpt('report_log_name',
+               default='patrole.log',
+               help="Name of file where output from 'enable_reporting' is "
+                    "logged. Note that this file is recreated on each "
+                    "invocation of patrole"),
+    cfg.StrOpt('report_log_path',
+               default='.',
+               help="Path (relative or absolute) where the output from "
+                    "'enable_reporting' is logged. This is combined with"
+                    "report_log_name to generate the full path."),
+]