all: use "context" instead of golang.org/x/net/context

Change-Id: I106c81a16eb5b39ff38c6f896095a27f597b3f8d
Reviewed-on: https://go-review.googlesource.com/99016
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/kubernetes/client_test.go b/kubernetes/client_test.go
index 91697c9..debf7f5 100644
--- a/kubernetes/client_test.go
+++ b/kubernetes/client_test.go
@@ -1,6 +1,7 @@
 package kubernetes_test
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -9,7 +10,6 @@
 
 	"golang.org/x/build/kubernetes"
 	"golang.org/x/build/kubernetes/api"
-	"golang.org/x/net/context"
 )
 
 type handlers []func(w http.ResponseWriter, r *http.Request) error