Cleanup cli.go because it is doing responsibility that config.go should do.
Bump number of goroutines when pushing to S3 to 100. Also handles edge case where putFileErr is not of type io.EOF but totally EOF.
Adds upload and download features.

Download pulls image from S3 and save it to -tempdir.

Upload push image from local directory to DOCKER_HOST.

Also, change a few method names to reflect what they actually do.
This is not needed.
Don’t auto generate subdirectory when we explicitly pass tempdir.
Cleanup upload command line interface to be more consistent.
updated readme
Updated help message
Put defer close(errch) inside goroutine function.
replace <repo name> to <image name> to reduce confusion.
Merge pull request #2 from newrelic-forks/download-upload-features

Download upload features