Initial commit based on current tempest

This creates the tempest plugin for horizon and duplicates
the existing horizon scenario test in tempest.

Change-Id: I9430b6cefc884ecc105e91ec19a07987aa70ef98
diff --git a/doc/source/readme.rst b/doc/source/readme.rst
new file mode 100644
index 0000000..a6210d3
--- /dev/null
+++ b/doc/source/readme.rst
@@ -0,0 +1 @@
+.. include:: ../../README.rst