title: Error 'import path does not begin with hostname' when building docker with local package
body: <p>I'm trying to build a docker with a local package but get the error 'import path does not begin with hostname'. If my understanding is correct, my Dockerfile should be just</p>
  
  <pre><code>FROM golang:onbuild
  EXPOSE 8080
  </code></pre>
  
  <p>based on this article <a href="https://blog.golang.org/docker">Deploying Go servers with Docker</a></p>
  
  <p>I use this code <a href="https://github.com/jadekler/git-go-websiteskeleton">git-go-websiteskeleton</a> as the source for building the docker. the full error is here.</p>
  
  <pre>
  import "git-go-websiteskeleton/app/common": import path does not begin with hostname
  package git-go-websiteskeleton/app/common: unrecognized import path "git-go-websiteskeleton/app/common"
  import "git-go-websiteskeleton/app/home": import path does not begin with hostname
  package git-go-websiteskeleton/app/home: unrecognized import path "git-go-websiteskeleton/app/home"
  import "git-go-websiteskeleton/app/user": import path does not begin with hostname
  package git-go-websiteskeleton/app/user: unrecognized import path "git-go-websiteskeleton/app/user"
  </pre>
  
  <p>Thank you for a help.</p>