Cannot load credentials

I've created owner credentials on ~/.aws/credentials on my mac but it throw an error

> [default]
> aws_access_key_id = MY_ACCESS_KEY_ID
> aws_secret_access_key = MY_SECRET_ACCESS_KEY

```
{ CredentialsError: Missing credentials in config
at ClientRequest. (/Volumes/Data/Loint/aws-nodejs-sample/node_modules/aws-sdk/lib/http/node.js:83:34)
at Object.onceWrapper (events.js:293:19)
at emitNone (events.js:86:13)
at ClientRequest.emit (events.js:188:7)
at Socket.emitTimeout (_http_client.js:679:10)
at Object.onceWrapper (events.js:293:19)
at emitNone (events.js:86:13)
at Socket.emit (events.js:188:7)
at Socket._onTimeout (net.js:352:8)
at ontimeout (timers.js:386:14)
message: 'Missing credentials in config',
code: 'CredentialsError',
time: 2017-10-13T10:42:38.188Z,
retryable: true,
originalError:
{ message: 'Could not load credentials from any providers',
code: 'CredentialsError',
time: 2017-10-13T10:42:38.188Z,
retryable: true,
originalError:
{ message: 'Missing credentials in config',
code: 'CredentialsError',
time: 2017-10-13T10:42:38.178Z,
retryable: true,
originalError: [Object] } } }
```

please help

未确定源文件、入口点或测试。使用 ~/.aws/credentials 重现所报告的 macOS 设置，并检查示例如何初始化 AWS SDK 以及加载凭证。完成标准是示例能够进行身份验证，且不再出现所报告的“Missing credentials in config”错误。

由索引模型根据 Issue 内容生成。