Enhance exception message assertions in TsoStartTest

Signed-off-by: Frank Giordano <giofr01@yahoo.com>

Author: frankgiordano

src/test/java/zowe/client/sdk/zostso/methods/TsoStartTest.java

@@ -98,7 +98,11 @@ public void tstTsoStartInvalidJsonThrowsZosmfRequestExceptionWithCorrectMessageF
 
             ZosmfRequestException ex = assertThrows(ZosmfRequestException.class,
                     () -> tsoStart.start(input));
+            assertNotNull(ex.getMessage());
             assertTrue(ex.getMessage().contains("invalid json response"));
+            assertTrue(ex.getMessage().contains("Unrecognized token")
+                            || ex.getMessage().toLowerCase().contains("json")
+            );
         }
     }