Add cleanup after creating keypair

There is no cleanup added after a keypair is created in test case
test_create_specify_keypair in test_servers.py which causes the test
case to leave behind a keypair when allow_tenant_isolation is false.
This issue is not observed when allow_tenant_isolation is true and
admin credentials are provided in tempest.conf as the tenant itself is
deleted after the test case ends.

Closes-Bug:1453112
Change-Id: Ia17f4dd2585c0d51540b05bcd9e08eec2757c1dd
Signed-off-by: ahmad <afaheem88@gmail.com>
diff --git a/tempest/api/compute/servers/test_servers.py b/tempest/api/compute/servers/test_servers.py
index b333122..31078e3 100644
--- a/tempest/api/compute/servers/test_servers.py
+++ b/tempest/api/compute/servers/test_servers.py
@@ -64,6 +64,7 @@
 
         key_name = data_utils.rand_name('key')
         self.keypairs_client.create_keypair(key_name)
+        self.addCleanup(self.keypairs_client.delete_keypair, key_name)
         self.keypairs_client.list_keypairs()
         server = self.create_test_server(key_name=key_name)
         self.client.wait_for_server_status(server['id'], 'ACTIVE')