trace: recommend the new import path for OpenCensus
// limitations under the License.
// This package is OBSOLETE. See https://godoc.org/go.opencensus.io/trace; and use
-// OpenCensus Stackdriver exporter, https://godoc.org/go.opencensus.io/exporter/stackdriver.
+// OpenCensus Stackdriver exporter, https://godoc.org/contrib.go.opencensus.io/exporter/stackdriver.
//
// Package trace is a Google Stackdriver Trace library.
//
