AWS assume role

[teddyking]

About

I am looking to use AWS Assume Role with bbl. I see there has been some work done in the past to add this support in (see the aws-assume-role-support branch), however it looks like that work never got merged into main.

I tried it out myself by rebasing that branch on top of main and building a local copy to see if it would work. I was able to successfully bbl up a director using the BBL_AWS_ASSUME_ROLE env var so thought I'd open this PR to get that work merged in.

cc @danielfor and @ystros who originally contributed the commits to the aws-assume-role-support branch.

[linux-foundation-easycla[bot]]

The committers listed above are authorized under a signed CLA.

• :white_check_mark: login: ystros / name: Brian Upton (1cb006272e93e9a0598466c11f92259684720b94, 7e724935d61be623ba3b565faa3fcf3e81292ce7)
• :white_check_mark: login: teddyking / name: Ed King (7b1477311e572e23c45d42f2ffd594e7550b4a15)
• :white_check_mark: login: danielfor / name: Daniel Felipe Ochoa (462a81c153e573b528654f0c0dff47f8cd81adbf)