Add copy restarts flag to ROMS driver (#630)

Author: aidanheerdegen

payu/models/roms.py

@@ -25,6 +25,8 @@ def __init__(self, expt, name, config):
         self.config_files = []
         self.optional_config_files = []
 
+        self.copy_restarts = True
+
     def setup(self):
         ## handle mandatory config files
         if 'model_config' not in self.config: