Adds initial hacking checks to Patrole

This patch:
  - Adds hacking check to Patrole (executed via tox -e pep8)
  - Corrects a few hacking errors
  - Adds hacking documentation to Patrole

Change-Id: Id43e24060a5290df91c594df6a38ba0cb239bbaf
diff --git a/HACKING.rst b/HACKING.rst
index bb337b0..b1d730d 100644
--- a/HACKING.rst
+++ b/HACKING.rst
@@ -1,6 +1,62 @@
 Patrole Style Commandments
 ==========================
 
-Read the OpenStack Style Commandments: `<http://docs.openstack.org/developer/hacking/>`__
+- Step 1: Read the OpenStack Style Commandments: `<http://docs.openstack.org/developer/hacking/>`__
+- Step 2: Review Tempest's Style Commandments: `<https://docs.openstack.org/developer/tempest/HACKING.html>`__
+- Step 3: Read on
 
-Also review Tempest's Style Commandments: `<https://docs.openstack.org/developer/tempest/HACKING.html>`__
+Patrole Specific Commandments
+------------------------------
+
+Patrole borrows the following commandments from Tempest; refer to
+`Tempest's Commandments <https://docs.openstack.org/developer/tempest/HACKING.html>`__
+for more information:
+
+.. note::
+
+    The original Tempest Commandments do not include Patrole-specific paths.
+    Patrole-specific paths replace the Tempest-specific paths within Patrole's
+    hacking checks.
+..
+
+- [T102] Cannot import OpenStack python clients in patrole_tempest_plugin/tests/api
+- [T105] Tests cannot use setUpClass/tearDownClass
+- [T106] vim configuration should not be kept in source files.
+- [T107] Check that a service tag isn't in the module path
+- [T108] Check no hyphen at the end of rand_name() argument
+- [T109] Cannot use testtools.skip decorator; instead use
+         decorators.skip_because from tempest.lib
+- [T113] Check that tests use data_utils.rand_uuid() instead of uuid.uuid4()
+- [N322] Method's default argument shouldn't be mutable
+
+The following are Patrole's specific Commandments:
+
+- [P100] The ``rbac_rule_validation.action`` decorator must be applied to
+         an RBAC test (the check fails if the decorator is not one of the
+         two decorators directly above the function declaration)
+- [P101] RBAC test filenames must end with "_rbac.py"; for example,
+         test_servers_rbac.py, not test_servers.py
+- [P102] RBAC test class names must end in 'RbacTest'
+
+Role Switching
+--------------
+
+Correct role switching is vital to correct RBAC testing within Patrole. If a
+test does not call ``rbac_utils.switch_role`` with ``toggle_rbac_role=True``
+within the RBAC test, then the test is *not* a valid RBAC test: The API
+endpoint under test will be performed with admin credentials, which is always
+wrong unless ``CONF.rbac_test_role`` is admin.
+
+.. note::
+
+    Switching back to the admin role for setup and clean up is automatically
+    performed. Toggling ``switch_role`` with ``toggle_rbac_role=False`` within
+    the context of a test should *never* be performed and doing so will likely
+    result in an error being thrown.
+..
+
+Patrole does not have a hacking check for role switching, but does use a
+built-in mechanism for verifying that role switching is being correctly
+executed across tests. If a test does not call ``switch_role`` with
+``toggle_rbac_role=True``, then an ``RbacResourceSetupFailed`` exception
+will be raised.