atlas post-processor unknown atlas.UploadartifactOpts field BuildId

in https://github.com/hashicorp/atlas-go/blob/master/v1/artifact.go
we can see it is BuildID and not BuildId

Signed-off-by: BlackEagle <ike.devolder@gmail.com>
Merge pull request #1747 from BlackIkeEagle/pp-atlas-unknown-buildId

atlas post-processor unknown atlas.UploadartifactOpts field BuildId