title: Golang dep unable to resolve dependencies
body: <p>I am using <a href="https://github.com/kubernetes-sigs/kubebuilder" rel="nofollow noreferrer">kubebuilder</a> to create kubernetes operator project. After running the project init command described in <a href="https://book.kubebuilder.io/quick_start.html" rel="nofollow noreferrer">quickstart guide</a></p>
  
  <pre><code>kubebuilder init --domain k8s.io --license apache2 --owner "The Kubernetes Authors"
  </code></pre>
  
  <p><code>dep ensure</code> returns with error log given below.</p>
  
  <pre><code>Solving failure: No versions of k8s.io/client-go met constraints:
      v8.0.0: Could not introduce k8s.io/client-go@v8.0.0, as it is not allowed by constraints from the following projects:
      kubernetes-1.10.1 from (root)
      kubernetes-1.10.1 from sigs.k8s.io/controller-runtime@master
  
      v7.0.0: Could not introduce k8s.io/client-go@v7.0.0, as it is not allowed by constraints from the following projects:
      kubernetes-1.10.1 from (root)
      kubernetes-1.10.1 from sigs.k8s.io/controller-runtime@master
  
      v6.0.0: Could not introduce k8s.io/client-go@v6.0.0, as it is not allowed by constraints from the following projects:
      kubernetes-1.10.1 from (root)
      kubernetes-1.10.1 from sigs.k8s.io/controller-runtime@master
  </code></pre>