text: Title: Create a CLI option to pass a configuration file path 
  Body: ## Description
  
  Create a CLI option to pass a configuration file path. Something like:
  
  ```bash
  scanapi --config-path <path_to_config_file>
  ```
  
  Current this file is called `SETTINGS_FILE`:
  https://github.com/scanapi/scanapi/blob/f27b031aa2f1fb4e9c85957e2c059733fabe69b8/scanapi/settings.py#L5
  
  Here is where we add new arguments to the CLI:
  https://github.com/scanapi/scanapi/blob/f27b031aa2f1fb4e9c85957e2c059733fabe69b8/scanapi/__init__.py#L13