def fetch_variables_config(path)
      descriptor = yaml_content(path)
      @variables = descriptor[::Knowledge.config.environment.to_s] || descriptor
    end
def fetch_variables_config(path)
      descriptor = yaml_content(path)
      @variables = descriptor[::Knowledge.config.environment.to_s] || descriptor
    end
Opens the config file and sets the variable config.

 === Parameters

 @param path [String]