Fix compilation errors in Flowable 5 Tests

Author: filiphr

modules/flowable5-test/src/main/java/org/activiti/engine/test/mock/MockElResolver.java

@@ -13,9 +13,6 @@
 
 package org.activiti.engine.test.mock;
 
-import java.beans.FeatureDescriptor;
-import java.util.Iterator;
-
 import org.flowable.common.engine.impl.javax.el.ELContext;
 import org.flowable.common.engine.impl.javax.el.ELResolver;
 
@@ -26,11 +23,6 @@ public Class<?> getCommonPropertyType(ELContext context, Object base) {
         return Object.class;
     }
 
-    @Override
-    public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext context, Object base) {
-        return null;
-    }
-
     @Override
     public Class<?> getType(ELContext context, Object base, Object property) {
         return null;