`s3:HeadBucket` is not a valid IAM Action in v4.x

[dkobia]

I'm not sure the s3:HeadBucket iam permission exists (or ever existed). Was this meant to be s3:ListBucket by any chance? Probably not because we have s3:List*.

jets/lib/jets/application/defaults.rb

Line 14 in 1e3fc14

action: ["s3:Get*", "s3:List*", "s3:HeadBucket"],

[tongueroo]

Good point. Seems like a bug/mistake. Will take PRs.