Should the argument in submission_tmpl() be hub_path instead of hub_con?

[annakrystalli]

Currently there is an option to provide either a hub_connection class object to hub_con, which has config_tasks attached as an attribute) or a config class object to config_tasks. It feels easier to just ask for hub_path instead of requiring folks to use hubData::connect_hub() to create a hub_connection given we only need the actual config_tasks object from the connection.

I would suggest we just do away with config_tasks (which also requires an extra step to read the config) and restrict the argument to hub_path only, then use read_config() internally to get the config.

This would also resolve #137