Docker connection configurable via cfg file
Merge remote-tracking branch 'GermanDZ/develop' into develop

Conflicts:
	cli/cli.go
	main.go
a couple of post-merge fixes
validate remotes

This is so we can avoid doing a lot of expensive work
(ie preparing the docker images) only to find out the
remote is misconfigured
use KeyPrefix in the validation

this is in case the bucket has a more restrictive
policy
oops
adds poster
Merge pull request #2 from blake-education/feature/logo

adds poster
print some help