log, vendor: vendor in log15 inline into our codebase

log/term/terminal_appengine.go

@@ -0,0 +1,13 @@
+// Based on ssh/terminal:
+// Copyright 2013 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.
+
+// +build appengine
+
+package term
+
+// IsTty always returns false on AppEngine.
+func IsTty(fd uintptr) bool {
+	return false
+}