add keypair fail

Add keypair fail in horizon.
But it still work at nova cli.

Following is keypair-add api request in log
2015-09-08 05:09:49.213635 REQ: curl -g -i 'http://10.20.0.105:8774/v2.1/c6d51ff62ef147aaa5ec7e7583de74c7/os-keypairs' -X POST -H "Accept: application/json" -H "Content-Type: application/json" -H "User-Agent: python-novaclient" -H "X-Auth-Project-Id: c6d51ff62ef147aaa5ec7e7583de74c7" -H "X-Auth-Token: {SHA1}bfc226cbca590d089f197b71fdcf88df5ea50175" -d '{"keypair": {"type": "ssh", "name": "d"}}'
2015-09-08 05:09:49.223710 RESP: [400] {'content-length': '190', 'x-compute-request-id': 'req-25eab1e0-20d7-4738-83ff-78061ce977bf', 'vary': 'X-OpenStack-Nova-API-Version', 'connection': 'keep-alive', 'x-openstack-nova-api-version': '2.1', 'date': 'Tue, 08 Sep 2015 05:09:49 GMT', 'content-type': 'application/json; charset=UTF-8'}
2015-09-08 05:09:49.223823 RESP BODY: null
2015-09-08 05:09:49.223882
2015-09-08 05:09:49.224676 Recoverable error: Invalid input for field/attribute keypair. Value: {u'type': u'ssh', u'name': u'd'}. Additional properties are not allowed (u'type' was unexpected) (HTTP 400) (Request-ID: req-25eab1e0-20d7-4738-83ff-78061ce977bf)

Body's schema is supported by api version above 2.2.
However horizon mark this request as 2.1 version.
Type is not allowed properties at 2.1.
Therefore this exception will been raised.

Besides nova cli is send 2.11 version, so it will work.