Fix references to dotcloud repo.

[pnasrat]

Fixes running tests in clean environment.

go test ./...
# github.com/docker/libchan
inmem_test.go:9:2: cannot find package "github.com/dotcloud/docker/pkg/testutils" in any of:
    /Users/pnasrat/Library/homebrew/Cellar/go/1.3/libexec/src/pkg/github.com/dotcloud/docker/pkg/testutils (from $GOROOT)
    /Users/pnasrat/go/src/github.com/dotcloud/docker/pkg/testutils (from $GOPATH)
FAIL    github.com/docker/libchan [setup failed]
# github.com/docker/libchan/unix
inmem_test.go:9:2: cannot find package "github.com/dotcloud/docker/pkg/testutils" in any of:
    /Users/pnasrat/Library/homebrew/Cellar/go/1.3/libexec/src/pkg/github.com/dotcloud/docker/pkg/testutils (from $GOROOT)
    /Users/pnasrat/go/src/github.com/dotcloud/docker/pkg/testutils (from $GOPATH)
FAIL    github.com/docker/libchan/unix [setup failed]
# github.com/docker/libchan/utils
inmem_test.go:9:2: cannot find package "github.com/dotcloud/docker/pkg/testutils" in any of:
    /Users/pnasrat/Library/homebrew/Cellar/go/1.3/libexec/src/pkg/github.com/dotcloud/docker/pkg/testutils (from $GOROOT)
    /Users/pnasrat/go/src/github.com/dotcloud/docker/pkg/testutils (from $GOPATH)
FAIL    github.com/docker/libchan/utils [setup failed]
ok      github.com/docker/libchan/data  0.006s
ok      github.com/docker/libchan/http2 0.045s

[dmcgowan]

The dotcloud repo is no longer referenced in imports after #38, but the contributing will still need to be updated.

[pnasrat]

Do you want me to rebase with the last fix or will you just do it yourself?

[dmcgowan]

I can, I just wanted to mention that I see the change and why I am not immediately merging

[pnasrat]

My opinion is master is the source of truth - get the patch merged and I could cut a doc patch, but if the pace of review is slow well it's not worth my time trying as you'll know when your PR is merged and then can clean up the single line doc.

[shykes]

LGTM

[pnasrat]

Now just doc fix

[dmcgowan]

LGTM