Replace godep with dep

vendor/golang.org/x/text/internal/testtext/gccgo.go

@@ -0,0 +1,11 @@
+// Copyright 2016 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 gccgo
+
+package testtext
+
+// AllocsPerRun always returns 0 for gccgo until gccgo implements escape
+// analysis equal or better to that of gc.
+func AllocsPerRun(runs int, f func()) (avg float64) { return 0 }