Forcibly delete ELASTICSEARCH_URL from environment to skip those tests unless --elasticsearch specified

runtests.py

@@ -49,6 +49,9 @@ def runtests():
 
     if args.elasticsearch:
         os.environ.setdefault('ELASTICSEARCH_URL', 'http://localhost:9200')
+    elif 'ELASTICSEARCH_URL' in os.environ:
+        # forcibly delete the ELASTICSEARCH_URL setting to skip those tests
+        del os.environ['ELASTICSEARCH_URL']
 
     argv = [sys.argv[0], 'test'] + args.rest
     try: