wip.
Working on it... [ci skip]
wip more changes.
More wip.
Merge branch 'master' into s3-configurator
More stuff.
[ci skip]
wip flesh out constraints section.
Finish out policy section.
Add spec for signature.
Remove test implementation.
Merge branch 'master' into s3-configurator
[#79863386] implement service according to spec
[#79863386] tidy up spec
[#79863386] second pass, stop mutating params

- can optionally override defaults like acl:

S3FormConfigurator.new(params) do
  self.acl = "write-only"
end
[#79863386] remove unnecessary result and form_json methods
Merge pull request #463 from Tahi-project/s3-configurator

[#79863386] S3 configurator