Load configuration

    The following steps will be undertake:
        * It will attempt to load configs from file:
          if `path` is provided, it will be used, otherwise the path
          will be taken from envvar `envvar_prefix` + "SETTINGS".
        * all envvars starting with `envvar_prefix` will be loaded.

def load_configs(envvar_prefix, path=None):
    '''Load configuration

    The following steps will be undertake:
        * It will attempt to load configs from file:
          if `path` is provided, it will be used, otherwise the path
          will be taken from envvar `envvar_prefix` + "SETTINGS".
        * all envvars starting with `envvar_prefix` will be loaded.

    '''
    conf = {}
    if path:
        conf.update(from_file(path))
    else:
        conf.update(from_envvar_file(envvar_prefix + "SETTINGS"))
    conf.update(from_envvars(prefix=envvar_prefix))
    return conf