Switch to using the dep tool and update all the dependencies

vendor/golang.org/x/crypto/sha3/xor.go

@@ -0,0 +1,16 @@
+// Copyright 2015 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 !amd64,!386,!ppc64le appengine
+
+package sha3
+
+var (
+	xorIn            = xorInGeneric
+	copyOut          = copyOutGeneric
+	xorInUnaligned   = xorInGeneric
+	copyOutUnaligned = copyOutGeneric
+)
+
+const xorImplementationUnaligned = "generic"