Added new test script for validating task service and tasks instance

Added validation for the following cases
- Validate attributes and default values in task service URI
- Trigger a redfish event that generates task instance and
 -- Verify task state is valid throughout task lifecycle
 -- Verify whether the start & end time for task is valid
 -- Verify the task monitor functionality in tasks instance
 -- Verify the payload properties in task instance
- Verify task collection persistency after BMC reboot

Tested: Run robot redfish/task_service/test_tasks.robot

Signed-off-by: Aravinth R <aravinthr@ami.com>
Change-Id: If9206e5eb9f624e7642d617664ef7af79bafc603
diff --git a/data/task_state.json b/data/task_state.json
index dd4c60f..14accd3 100644
--- a/data/task_state.json
+++ b/data/task_state.json
@@ -1,15 +1,52 @@
 {
-        "comment": "This is a generic possible redfish standard task states.",
-        "TaskRunning": {
-                "TaskState": "Running",
-                "TaskStatus": "OK"
+    "comment": "This is a generic possible redfish standard task states.",
+    "TaskRunning": {
+        "TaskState": "Running",
+        "TaskStatus": "OK"
+    },
+    "TaskCompleted": {
+        "TaskState": "Completed",
+        "TaskStatus": "OK"
+    },
+    "TaskException": {
+        "TaskState": "Exception",
+        "TaskStatus": "Warning"
+    },
+    "TaskService": {
+        "CompletedTaskOverWritePolicy": {
+            "AllowedValues": [
+                "Manual",
+                "Oldest"
+            ]
         },
-        "TaskCompleted": {
-                "TaskState": "Completed",
-                "TaskStatus": "OK"
-        },
-        "TaskException": {
-                "TaskState": "Exception",
-                "TaskStatus": "Warning"
+        "Status": {
+            "Health": "OK",
+            "HealthRollup": "OK",
+            "State": "Enabled"
         }
-}
+    },
+    "Task": {
+        "TaskState": {
+            "AllowedValues": [
+                "New",
+                "Starting",
+                "Running",
+                "Suspended",
+                "Interrupted",
+                "Pending",
+                "Stopping",
+                "Completed",
+                "Killed",
+                "Exception",
+                "Service",
+                "Cancelling",
+                "Cancelled"
+            ],
+            "AllowedCompletionTaskState": [
+                "Cancelled",
+                "Completed",
+                "Exception"
+            ]
+        }
+    }
+}
\ No newline at end of file