Removed the setServiceDirectory() method from the base web resource

This is a testing only API and potentially dangerous to allow to be public.
I modified the tests that use it to set the value using TestUtils.setField()

Change-Id: Ic590f4641f4e3de208dffa16b3df9a9a2106114b
diff --git a/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/MappingsWebResourceTest.java b/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/MappingsWebResourceTest.java
index d2f4c86..4d5f06d 100644
--- a/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/MappingsWebResourceTest.java
+++ b/apps/mappingmanagement/web/src/test/java/org/onosproject/mapping/web/MappingsWebResourceTest.java
@@ -30,7 +30,6 @@
 import org.onlab.osgi.ServiceDirectory;
 import org.onlab.osgi.TestServiceDirectory;
 import org.onlab.packet.IpPrefix;
-import org.onlab.rest.BaseResource;
 import org.onosproject.codec.CodecService;
 import org.onosproject.codec.impl.CodecManager;
 import org.onosproject.mapping.DefaultMappingKey;
@@ -278,7 +277,7 @@
                         .add(DeviceService.class, mockDeviceService)
                         .add(CodecService.class, codecService);
 
-        BaseResource.setServiceDirectory(testDirectory);
+        setServiceDirectory(testDirectory);
     }
 
     /**