Creates a `Config` from `fpath`.

def create(cls, fpath):
        "Creates a `Config` from `fpath`."
        fpath = _expand_path(fpath)
        assert(fpath.suffix == '.yml')
        if fpath.exists(): return
        fpath.parent.mkdir(parents=True, exist_ok=True)
        with open(fpath, 'w') as yaml_file:
            yaml.dump(cls.DEFAULT_CONFIG, yaml_file, default_flow_style=False)