Fix docs warnings of auth

This commit fixes some docs auth warnings[1] such as
 * Field list ends without a blank line; unexpected unindent
 * Unexpected indentation
 * Block quote ends without a blank line; unexpected unindent
 * document isn't included in any toctree
[1]:
http://logs.openstack.org/79/327579/1/check/gate-tempest-docs/fb1e2bd/console.html#_2016-06-09_22_25_45_335

Change-Id: I78b52a7c737c9fae12040321861aaeef2e3513cb
diff --git a/doc/source/library.rst b/doc/source/library.rst
index a89512c..6a2fb83 100644
--- a/doc/source/library.rst
+++ b/doc/source/library.rst
@@ -66,3 +66,4 @@
    library/rest_client
    library/utils
    library/api_microversion_testing
+   library/auth