use relative protocol for s3 upload
restructure the aws s3 url to be able to use secure protocol
prepends url with s3
Merge branch 'master' of github.com:G5/g5-content-management-system into asset-uploader-protocol-72897194
removes trailing slash from s3 url
adds back trailing slash, removes region from the json for signing accuracy
prefixes upload url with s3
adds hyphen to s3 upload url
evaluates `now` once and stores it for the life of the signer instance
adds region to delivered json, removes it for the external request
Merge branch 'master' of github.com:G5/g5-content-management-system into asset-uploader-protocol-72897194
Merge branch 'master' of github.com:G5/g5-content-management-system into asset-uploader-protocol-72897194
Merge pull request #372 from G5/asset-uploader-protocol-72897194

[WIP] Asset uploader protocol 72897194