implement everything in Go

[smothiki]

because of beta crunch time we haven;t explored enough options to use a go cli based client to build docker images and PUSH to remote registry. Also moving a head in the future we have to support multiple object storage backends. Also add support to talk to remote docker deamon along with mounting docker socker

[mboersma]

This would be a nice refactoring, and @smothiki thinks it is possible now that Docker's cli interface may not be locked to a specific release. But it's not happening for the Workflow 2.0 release so I'm removing this milestone.

[Cryptophobia]

This issue was moved to teamhephy/dockerbuilder#7