Extend supported regions.

[mmzx]

Please see diff.

[mmzx]

ping @bernardd

[jgoering]

@bernardd would it be possible to release a new version with updated region support soon? I would greatly appreciate it, since otherwise we need to go through a lengthy approval process with our security teams to switch to a fork.

Let me know if there is anything else we can help with in this regard. I think there are also others who would be interested in this, see https://github.com/ex-aws/ex_aws/pull/1050 and https://github.com/ex-aws/ex_aws/pull/1051

[bernardd]

Hi @mmzx - thanks for the PR and apologies for the delay getting to it.

[mmzx]

Thank you @bernardd!

[jgoering]

Thank you @bernardd !