instagram: add Instagram endpoints

Change-Id: Ibb180f48013a398d597f56e14f081842735957df
GitHub-Last-Rev: 2d643292768610cdb5896827270dcd4a71da3572
GitHub-Pull-Request: golang/oauth2#304
Reviewed-on: https://go-review.googlesource.com/125639
Reviewed-by: Tim Cooper <tim.cooper@layeh.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/instagram/instagram.go b/instagram/instagram.go
new file mode 100644
index 0000000..75a74eb
--- /dev/null
+++ b/instagram/instagram.go
@@ -0,0 +1,16 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package instagram provides constants for using OAuth2 to access Instagram.
+package instagram // import "golang.org/x/oauth2/instagram"
+
+import (
+	"golang.org/x/oauth2"
+)
+
+// Endpoint is Instagram's OAuth 2.0 endpoint.
+var Endpoint = oauth2.Endpoint{
+	AuthURL:  "https://api.instagram.com/oauth/authorize",
+	TokenURL: "https://api.instagram.com/oauth/access_token",
+}