fix: Promenade exceptions documentation incorrectly rendering

This patch set changes Promenade's exceptions documentation
(contained underneath operators guide) because it isn't rendering
correctly as a list table on RTD (the autoexception information
is missing) [0].

The easy fix is to change the tabularized view (list table)
into basically a series of autoexception classes which sufficiently
captures the level of detail required, anyway.

Note that running `tox -e docs` locally and opening the resulting
index.html page appears to work -- but not when hosted on RTD.

[0] https://airship-promenade.readthedocs.io/en/latest/exceptions.html

Change-Id: Idefb43d230f11194df863f72aea06f7f153313f9

doc/source/exceptions.rst

@@ -18,39 +18,32 @@
 Promenade Exceptions
 ====================
 
-.. list-table::
+.. autoexception:: promenade.exceptions.ApiError
-  :widths: 5 50
+   :members:
-  :header-rows: 1
+   :show-inheritance:
+   :undoc-members:
 
-  * - Exception Name
+.. autoexception:: promenade.exceptions.InvalidFormatError
-    - Description
+   :members:
-  * - ApiError
+   :show-inheritance:
-    - .. autoexception:: promenade.exceptions.ApiError
+   :undoc-members:
-         :members:
+
-         :show-inheritance:
+.. autoexception:: promenade.exceptions.ValidationException
-         :undoc-members:
+   :members:
-  * - InvalidFormatError
+   :show-inheritance:
-    - .. autoexception:: promenade.exceptions.InvalidFormatError
+   :undoc-members:
-        :members:
+
-        :show-inheritance:
+.. autoexception:: promenade.exceptions.KubernetesConfigException
-        :undoc-members:
+   :members:
-  * - ValidationException
+   :show-inheritance:
-    - .. autoexception:: promenade.exceptions.ValidationException
+   :undoc-members:
-        :members:
+
-        :show-inheritance:
+.. autoexception:: promenade.exceptions.KubernetesApiError
-        :undoc-members:
+   :members:
-  * - KubernetesConfigException
+   :show-inheritance:
-    - .. autoexception:: promenade.exceptions.KubernetesConfigException
+   :undoc-members:
-        :members:
+
-        :show-inheritance:
+.. autoexception:: promenade.exceptions.NodeNotFoundException
-        :undoc-members:
+   :members:
-  * - KubernetesApiError
+   :show-inheritance:
-    - .. autoexception:: promenade.exceptions.KubernetesApiError
+   :undoc-members:
-        :members:
-        :show-inheritance:
-        :undoc-members:
-  * - NodeNotFoundException
-    - .. autoexception:: promenade.exceptions.NodeNotFoundException
-        :members:
-        :show-inheritance:
-        :undoc-members: