Adds Designate server tests

This submission adds three methods to
rally/benchmark/scenarios/designate/basic.py
1) def create_and_list_servers
2) def list_servers
3) def create_and_delete_servers

Also, Adds methods to "utils.py" under
"rally/benchmark/scenarios/designate"
1) def _create_server
2) def _list_servers
3) def _delete_server

Added configuration files for server operations under
samples/tasks/scenarios/designate
1) create-and-delete-servers.json
2) create-and-delete-servers.yaml
3) create-and-list-servers.json
4) create-and-list-servers.yaml

Added unittests to test_utils.py, test_basic.py under
tests/unit/benchmark/scenarios/designate

Change-Id: I802b40b87aa064ac138b97395e3e56da40f33d74

rally-jobs/rally-designate.yaml

@@ -72,3 +72,31 @@
       sla:
         failure_rate:
           max: 0
+
+  DesignateBasic.create_and_list_servers:
+    -
+      runner:
+        type: "constant"
+        times: 10
+        concurrency: 1
+      context:
+        users:
+          tenants: 2
+          users_per_tenant: 2
+      sla:
+        failure_rate:
+          max: 0
+
+  DesignateBasic.create_and_delete_server:
+    -
+      runner:
+        type: "constant"
+        times: 10
+        concurrency: 1
+      context:
+        users:
+          tenants: 2
+          users_per_tenant: 2
+      sla:
+        failure_rate:
+          max: 0

samples/tasks/scenarios/designate/create-and-delete-server.json

@@ -0,0 +1,17 @@
+{
+    "DesignateBasic.create_and_delete_server": [
+        {
+            "runner": {
+                "type": "constant",
+                "times": 10,
+                "concurrency": 1
+            },
+            "context": {
+                "users": {
+                    "tenants": 2,
+                    "users_per_tenant": 2
+                }
+            }
+        }
+    ]
+}

samples/tasks/scenarios/designate/create-and-delete-server.yaml

@@ -0,0 +1,11 @@
+---
+  DesignateBasic.create_and_delete_server:
+    -
+      runner:
+        type: "constant"
+        times: 10
+        concurrency: 1
+      context:
+        users:
+          tenants: 2
+          users_per_tenant: 2

samples/tasks/scenarios/designate/create-and-list-servers.json

@@ -0,0 +1,17 @@
+{
+    "DesignateBasic.create_and_list_servers": [
+        {
+            "runner": {
+                "type": "constant",
+                "times": 10,
+                "concurrency": 1
+            },
+            "context": {
+                "users": {
+                    "tenants": 2,
+                    "users_per_tenant": 2
+                }
+            }
+        }
+    ]
+}

samples/tasks/scenarios/designate/create-and-list-servers.yaml

@@ -0,0 +1,11 @@
+---
+  DesignateBasic.create_and_list_servers:
+    -
+      runner:
+        type: "constant"
+        times: 10
+        concurrency: 1
+      context:
+        users:
+          tenants: 2
+          users_per_tenant: 2