Fix failing unit tests

Author: jbarrez

modules/flowable-cmmn-rest/src/test/java/org/flowable/cmmn/rest/service/api/history/HistoricPlanItemInstanceResourcesTest.java

@@ -162,6 +162,8 @@ public void testHistoricPlanItemInstanceResource() {
                         + "  endedTime: null,"
                         + "  lastUpdatedTime: '${json-unit.any-string}',"
                         + "  startUserId: null,"
+                        + "  assignee: null,"
+                        + "  completedBy: null,"
                         + "  referenceId: null,"
                         + "  referenceType: null,"
                         + "  entryCriterionId: null,"
@@ -213,6 +215,8 @@ public void testHistoricPlanItemInstanceResource() {
                         + "  endedTime: null,"
                         + "  lastUpdatedTime: '${json-unit.any-string}',"
                         + "  startUserId: null,"
+                        + "  assignee: null,"
+                        + "  completedBy: null,"
                         + "  referenceId: null,"
                         + "  referenceType: null,"
                         + "  entryCriterionId: null,"
@@ -264,6 +268,8 @@ public void testHistoricPlanItemInstanceResource() {
                         + "  endedTime: null,"
                         + "  lastUpdatedTime: '${json-unit.any-string}',"
                         + "  startUserId: null,"
+                        + "  assignee: null,"
+                        + "  completedBy: null,"
                         + "  referenceId: '${json-unit.any-string}',"
                         + "  referenceType: 'cmmn-1.1-to-cmmn-1.1-child-human-task',"
                         + "  entryCriterionId: null,"