Switch to native S3 library to use IAM for permissions

[warhammerkid]

It looks like the library you're using to interact with S3, knox, is not maintained, and is therefore missing common functionality like IAM role support. If you switched to using the AWS SDK, you would be able to get that functionality without any additional effort.

[stephenyeargin]

Hmm. Not sure how all that's configured @raventools, but we haven't had any trouble issuing a credential for the bot.

[stephenyeargin]

For reference, this is discussed here as well on the knox repository: Automattic/knox#262 . You're probably right about it not being actively maintained.

There are apparently a fair number of pros/cons to using the native AWS node package. The biggest concern I have is for folks who have implemented S3-like services, such as Pithos, would no longer be able to use the package. (#35)

It doesn't look terribly difficult to accomplish, but it will need some more research.

[warhammerkid]

I have not worked with any of the S3-like services, but so long as they're truly compatible, you should be able to use the endpoint option for the S3 constructor (http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/S3.html#constructor-property) to point to your own server.