Convert generated-deep-copies to use golang.org/x/tools/imports

I don't like users to need an external binary which can easily get out
of sync. Just include the tools.

pkg/expapi/deep_copy_generated.go

@@ -14,9 +14,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// DO NOT EDIT. THIS FILE IS AUTO-GENERATED BY $KUBEROOT/hack/update-generated-deep-copies.sh.
+
 package expapi
 
-// AUTO-GENERATED FUNCTIONS START HERE
 import (
 	time "time"
 
@@ -232,5 +233,3 @@ func init() {
 		panic(err)
 	}
 }
-
-// AUTO-GENERATED FUNCTIONS END HERE