S3 test refactor, acl and compose support, linting
S3 test refactor, acl and compose support, linting

fishjord/gsutil,dtjackson/gsutil,ttiurani/gsutil,GoogleCloudPlatform/gsutil,GoogleCloudPlatform/gsutil,dimfeld/gsutil,chriskuehl/gsutil-debian,BrandonY/gsutil,craigcitro/gsutil,mattdr/gsutil