string issue fix for few yang construct like config, mandatory + allowing yang constructs as identifers and string

Change-Id: I8dd01dc60d280a843b0a485681caa6bfcac013c2
diff --git a/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListenerTest.java b/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListenerTest.java
index b197557..7f4a6f6 100644
--- a/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListenerTest.java
+++ b/src/test/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListenerTest.java
@@ -111,7 +111,7 @@
     @Test
     public void processMinElementsInvalidValue() throws IOException, ParserException {
         thrown.expect(ParserException.class);
-        thrown.expectMessage("mismatched input 'asd' expecting INTEGER");
+        thrown.expectMessage("YANG file error : min-elements value asd is not valid.");
         YangNode node = manager.getDataModel("src/test/resources/MinElementsInvalidValue.yang");
     }