test_ec2_list_credentials does a wrong test

[wanghong]

https://github.com/openstack/keystone/blob/master/keystone/tests/test_v3_credential.py#L370
    def test_ec2_list_credentials(self):
        """Test ec2 credential listing."""
        self._get_ec2_cred_uri()
        uri = self._get_ec2_cred_uri()
        r = self.get(uri)
        cred_list = r.result
        self.assertEqual(1, len(cred_list))
According to current code, I think the test steps is:
1. create a ec2 credential
2. list all credentials
3. assert that list method can get the ec2 credential created before
But, the author used a wrong method to create ec2 credential and asserted the wrong data:
1. The method which creates a ec2 credential is self._get_ec2_cred()
2. cred_list should be r.result['credentials']

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/149134

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/149134
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=4ae80da2af2a2c9b6245be3e3e638337b96f011c
Submitter: Jenkins
Branch: master

commit 4ae80da2af2a2c9b6245be3e3e638337b96f011c
Author: wanghong <email address hidden>
Date: Thu Jan 22 12:11:57 2015 +0800

    fix test_ec2_list_credentials

    The author used a wrong method to create ec2 credential and asserted
    the wrong list data:
    1. The method which creates a ec2 credential is self._get_ec2_cred()
    2. cred_list should be r.result['credentials']

    Change-Id: Ibb934ea404654adc99220096edf913a8aa8df7b3
    Closes-Bug: #1413459