add created to listworkflowinstanceresponse

nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/converter/ListWorkflowInstanceConverter.java

@@ -41,6 +41,7 @@ public ListWorkflowInstanceResponse convert(WorkflowInstance instance, QueryWork
     resp.state = instance.state;
     resp.stateText = instance.stateText;
     resp.nextActivation = instance.nextActivation;
+    resp.created = instance.created;
     if (query.includeActions) {
       resp.actions = new ArrayList<>();
       for (WorkflowInstanceAction action : instance.actions) {

nflow-rest-api/src/main/java/com/nitorcreations/nflow/rest/v1/msg/ListWorkflowInstanceResponse.java

@@ -41,6 +41,6 @@ public class ListWorkflowInstanceResponse {
   @ApiModelProperty(value = "State change attempts. One instance for each processing attempt.", required=false)
   public List<Action> actions;
 
-
-
+  @ApiModelProperty(value = "Workflow instance creation timestamp", required=true)
+  public DateTime created;
 }

nflow-rest-api/src/test/java/com/nitorcreations/nflow/rest/v1/converter/ListWorkflowInstanceConverterTest.java

@@ -69,6 +69,7 @@ public void convertWithActionsWorks() throws IOException {
     assertThat(resp.state, is(i.state));
     assertThat(resp.stateText, is(i.stateText));
     assertThat(resp.nextActivation, is(i.nextActivation));
+    assertThat(resp.created, is(i.created));
     assertThat(resp.actions, contains(reflectEquals(new Action(a.state, a.stateText, a.retryNo,
         a.executionStart, a.executionEnd))));
   }