老师，在执行vue init webpack my-project命令时，报错：SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode    at exports.runInThisContext (vm.js:53:16)    at Module._compile (module.js:373:25)    at Object.Module._extensions..js (module.js:416:10)等 这个怎么解决啊