Use github.com/juju/names package

Also remove unnecessary usage of errors package when fmt was already imported.
Fix test imports
Update dependencies.tsv
fix imports test
Merge branch 'master' of https://github.com/juju/juju into 102-remove-juju-names

Conflicts:
	provider/dummy/environs.go
	state/environ.go
	state/networkinterfaces.go
	state/networks.go
	state/relation.go
	state/relationunit.go
Merge pull request #34 from davecheney/102-remove-juju-names

Also remove unnecessary usage of errors package when fmt was already imported.