title: dep ensure removing the install folders
body: <p>I have installed the httprouter package using the following command</p>
  
  <pre><code>dep ensure -add github.com/julienschmidt/httprouter
  
        vendor
          └── github.com
              ├── julienschmidt
              │   └── httprouter
  </code></pre>
  
  <p>Then I have installed the uuid package</p>
  
  <pre><code>dep ensure -add github.com/satori/go.uuid
    vendor
          └── github.com
              ├── satori
  </code></pre>
  
  <p>The julienschmidt router package gone away. Why dep is deleting the previous installation ?</p>
  
  <p>Deleting the entry on Gopkg.lock</p>
  
  <p>Gopkg.toml has this entry</p>
  
  <pre><code>[[constraint]]
    name = "github.com/julienschmidt/httprouter"
    version = "1.1.0"
  
  [[constraint]]
    name = "github.com/satori/go.uuid"
    version = "1.2.0"
  </code></pre>
  
  <p>Will this affect anything ?</p>
  
  <p>My directory structure</p>
  
  <pre><code>gopath/src/github.com
  - services
    - service-auth
    - service-signup
  - vendor
     - github.com
  </code></pre>
  
  <p>Thanks.</p>