add server delete/unpause tests

add an expected behaviour test of deleting server
- delete_active_server
add two negative tests for server unpausing
- unpause_non_existent_server
- unpause_server_invalid_state

Change-Id: Ia9b5fdf1c2298ff685322fc99a5496710a7a67ef
diff --git a/tempest/api/compute/servers/test_servers.py b/tempest/api/compute/servers/test_servers.py
index 625964c..5ce51c0 100644
--- a/tempest/api/compute/servers/test_servers.py
+++ b/tempest/api/compute/servers/test_servers.py
@@ -112,6 +112,13 @@
         resp, _ = self.client.delete_server(server['id'])
         self.assertEqual('204', resp['status'])
 
+    @attr(type='gate')
+    def test_delete_active_server(self):
+        # Delete a server while it's VM state is Active
+        resp, server = self.create_server(wait_until='ACTIVE')
+        resp, _ = self.client.delete_server(server['id'])
+        self.assertEqual('204', resp['status'])
+
 
 class ServersTestXML(ServersTestJSON):
     _interface = 'xml'
diff --git a/tempest/api/compute/servers/test_servers_negative.py b/tempest/api/compute/servers/test_servers_negative.py
index e864343..b3e17cb 100644
--- a/tempest/api/compute/servers/test_servers_negative.py
+++ b/tempest/api/compute/servers/test_servers_negative.py
@@ -16,6 +16,7 @@
 #    under the License.
 
 import sys
+import uuid
 
 from tempest.api.compute import base
 from tempest import clients
@@ -258,16 +259,29 @@
     @attr(type=['negative', 'gate'])
     def test_stop_non_existent_server(self):
         # Stop a non existent server
-        non_exist_id = rand_name('non-existent-server')
         self.assertRaises(exceptions.NotFound, self.servers_client.stop,
-                          non_exist_id)
+                          str(uuid.uuid4()))
 
     @attr(type=['negative', 'gate'])
     def test_pause_non_existent_server(self):
         # pause a non existent server
-        non_exist_id = rand_name('non-existent-server')
         self.assertRaises(exceptions.NotFound, self.client.pause_server,
-                          non_exist_id)
+                          str(uuid.uuid4()))
+
+    @attr(type=['negative', 'gate'])
+    def test_unpause_non_existent_server(self):
+        # unpause a non existent server
+        self.assertRaises(exceptions.NotFound, self.client.unpause_server,
+                          str(uuid.uuid4()))
+
+    @attr(type=['negative', 'gate'])
+    def test_unpause_server_invalid_state(self):
+        # unpause an active server.
+        resp, server = self.create_server(wait_until='ACTIVE')
+        server_id = server['id']
+        self.assertRaises(exceptions.Duplicate,
+                          self.client.unpause_server,
+                          server_id)
 
 
 class ServersNegativeTestXML(ServersNegativeTestJSON):