Add test documentation for docs tox target

Enable sphinx to generate documentation from docstrings by running
'tox -e docs'.

Change-Id: I5996e5f07493f69f14172b4bb0535852e89d5456
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 2349713..88b9718 100755
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -15,7 +15,14 @@
 import os
 import sys
 
-sys.path.insert(0, os.path.abspath('../..'))
+def autodoc_skip_member_handler(app, what, name, obj, skip, options):
+    return skip or (what == "class" and not name.startswith("test"))
+
+def setup(app):
+    app.connect('autodoc-skip-member', autodoc_skip_member_handler)
+
+sys.path.insert(0, os.path.abspath('../../neutron_tempest_plugin'))
+
 # -- General configuration ----------------------------------------------------
 
 # Add any Sphinx extension module names here, as strings. They can be
diff --git a/doc/source/index.rst b/doc/source/index.rst
index 91388a9..e69a4ec 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -15,6 +15,7 @@
    readme
    installation
    contributing
+   test_descriptions
 
 Indices and tables
 ==================
diff --git a/doc/source/test_descriptions.rst b/doc/source/test_descriptions.rst
new file mode 100644
index 0000000..240e448
--- /dev/null
+++ b/doc/source/test_descriptions.rst
@@ -0,0 +1,7 @@
+Description of Tests
+====================
+
+.. toctree::
+   :maxdepth: 2
+
+   tests/modules