Add an option to run the inst script main() with default args

This fixes the test failure when `main()` is imported and run as a
module in `osf_tests/test_elastic_search.py::TestSearchMigration`
by setting `default_args=True` during setup. Running the script via
command line is not affected using `default_args=False`.

osf_tests/test_elastic_search.py

@@ -1307,7 +1307,7 @@ def tearDownClass(cls):
 
     def setUp(self):
         super(TestSearchMigration, self).setUp()
-        populate_institutions('test')
+        populate_institutions(default_args=True)
         self.es = search.search_engine.CLIENT
         search.delete_index(settings.ELASTIC_INDEX)
         search.create_index(settings.ELASTIC_INDEX)

scripts/populate_institutions.py

@@ -54,9 +54,13 @@ def update_or_create(inst_data):
         return inst, True
 
 
-def main():
+def main(default_args=False):
+
+    if default_args:
+        args = parser.parse_args(['--env', 'test', '--all'])
+    else:
+        args = parser.parse_args()
 
-    args = parser.parse_args()
     server_env = args.env
     update_ids = args.ids
     update_all = args.all
@@ -1661,4 +1665,4 @@ def main():
 
 if __name__ == '__main__':
 
-    main()
+    main(default_args=False)