[Plugins] Class-based scenario DummyFailure

This adds the first class-based scenario.

Change-Id: Ia1a0ea6988b21f792070ac15e425dc52441ff4c2
Implements: class-based-scenarios

rally-jobs/rally.yaml

@@ -672,6 +672,26 @@
           action_3: 4.0
           action_4: 5.0
 
+  dummy.failure:
+    -
+      args:
+        sleep: 0.2
+        from_iteration: 5
+        to_iteration: 15
+        each: 2
+      runner:
+        type: "constant"
+        times: 20
+        concurrency: 5
+      context:
+        users:
+          tenants: 1
+          users_per_tenant: 1
+      sla:
+        failure_rate:
+          min: 25
+          max: 25
+
   FakePlugin.testplugin:
     -
       runner:

samples/tasks/scenarios/dummy/dummy-failure.json

@@ -0,0 +1,23 @@
+{
+    "dummy.failure": [
+        {
+            "args": {
+                "sleep": 0.2,
+                "from_iteration": 5,
+                "to_iteration": 10,
+                "each": 2
+            },
+            "runner": {
+                "type": "constant",
+                "times": 20,
+                "concurrency": 5
+            },
+            "context": {
+                "users": {
+                    "tenants": 1,
+                    "users_per_tenant": 1
+                }
+            }
+        }
+    ]
+}

samples/tasks/scenarios/dummy/dummy-failure.yaml

@@ -0,0 +1,16 @@
+---
+  dummy.failure:
+    -
+      args:
+        sleep: 0.2
+        from_iteration: 5
+        to_iteration: 10
+        each: 2
+      runner:
+        type: "constant"
+        times: 20
+        concurrency: 5
+      context:
+        users:
+          tenants: 1
+          users_per_tenant: 1