This fix updates aws-sdk-go and go-ini to recent versions.
The aws-sdk-go used to be `v1.4.22` which was more than a
year old, and go-ini used to be pre-1.0 release.
This fix updates aws-sdk-go to v1.12.66 and go-ini to v1.25.4:
```
github.com/aws/aws-sdk-go v1.12.66
github.com/go-ini/ini v1.25.4
```
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
