Fixing failing REST-test for task variable (missing BPMN)

modules/activiti-rest/src/test/resources/org/activiti/rest/api/runtime/TaskVariableResourceTest.testGetTaskVariable.bpmn20.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<definitions
+  xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
+  xmlns:activiti="http://activiti.org/bpmn"
+  targetNamespace="OneTaskCategory">
+
+  <process id="oneTaskProcess" name="The One Task Process">
+    <documentation>One task process description</documentation>
+  
+    <startEvent id="theStart" />
+    <sequenceFlow id="flow1" sourceRef="theStart" targetRef="processTask" />
+    <userTask id="processTask" name="Process task" activiti:candidateUsers="kermit" activiti:candidateGroups="sales">
+       <documentation>Process task description</documentation>
+    </userTask>    
+    <sequenceFlow id="flow2" sourceRef="processTask" targetRef="theEnd" />
+    <endEvent id="theEnd" />
+    
+  </process>
+
+</definitions>
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