Remove releases.rst from keystone docs

The most recent update to releases.rst was made back in 2012,
but it's references in the docs page. It is providing false
(or at least, inaccurate) information. Suggest removing it
since the server side doesn't have a release related file either.

Change-Id: If2a71b55117c450afdade3cad697eba5a626263f

doc/source/index.rst

@@ -11,7 +11,6 @@ Contents:
 .. toctree::
    :maxdepth: 1
 
-   releases
    man/keystone
    using-api-v2
    using-api-v3

doc/source/releases.rst

@@ -1,33 +0,0 @@
-=============
-Release notes
-=============
-
-0.1.3 (August 31, 2012)
-=======================
-* changed logging to report request and response independently in --debug mode
-* changed options to use hyphens instead of underscores
-* added support for PKI signed tokens with Keystone
-
-
-0.1.2 (July 9, 2012)
-====================
-* added support for two-way SSL and --insecure option to allow for self-signed
-  certificates
-* added support for password prompting if not provided
-* added support for bash completion for keystone
-* updated CLI options to use dashes instead of underscores
-
-0.1.1 (June 25, 2012)
-=====================
-* corrected versioning
-
-0.1.0 (March 29, 2012)
-======================
-* released with OpenStack Essex and Diablo compatibility
-* forked from http://github.com/rackspace/python-novaclient
-* refactored to support Identity API (auth, tokens, services, roles, tenants,
-  users, etc.)
-* removed legacy arguments of --username, --password, etc in migration to
-  support a cross-openstack unified CLI convention defined at
-  http://wiki.openstack.org/UnifiedCLI
-* required service ID for listing endpoints