Be specific in Gopkg.toml, update

This commit makes sure we're specific on what packages we "require" in
Gopkg.toml.  Erroneously requiring the root package in the
apiextensions-apiserver, was causing us to pull in main, and
transitively a whole bunch of deps that we didn't actually need.

Gopkg.toml

@@ -13,13 +13,18 @@
 #  limitations under the License.
 
 # Packages required by users
+# NB(directxman12): be very careful how you word these --
+# dep considers them as a dependency on the package you list
+# meaning that if there's a main.go in the root package
+# (like in apiextensions-apiserver), you'll pull it's deps in.
 required = ["sigs.k8s.io/testing_frameworks/integration",
             "k8s.io/client-go/plugin/pkg/client/auth",
             "github.com/spf13/pflag",
             "github.com/emicklei/go-restful",
             "github.com/go-openapi/spec",
             "k8s.io/kube-openapi/pkg/common",
-            "k8s.io/apiextensions-apiserver",
+            "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1",
+            "k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset",
             "github.com/prometheus/client_golang/prometheus",
             ]