Defect fix for YANG revision

Change-Id: I6af5e82122629ea69c40b4fc3159bc7712d8293d
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java
index 2159888..ef302be 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java
@@ -17,6 +17,7 @@
 package org.onosproject.yangutils.parser.impl.listeners;
 
 import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangRevision;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
@@ -30,6 +31,7 @@
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.setCurrentDateForRevision;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsEmpty;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.utils.YangConstructType.MODULE_DATA;
@@ -85,6 +87,13 @@
             yangModule.setVersion((byte) 1);
         }
 
+        if (ctx.moduleBody().revisionStatements().revisionStatement().isEmpty()) {
+            String currentDate = setCurrentDateForRevision();
+            YangRevision currentRevision = new YangRevision();
+            currentRevision.setRevDate(currentDate);
+            yangModule.setRevision(currentRevision);
+        }
+
         listener.getParsedDataStack().push(yangModule);
     }