fixed dependencies

vendor/gonum.org/v1/gonum/internal/math32/signbit.go

@@ -0,0 +1,16 @@
+// Copyright 2010 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.
+
+// Copyright ©2017 The Gonum 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 math32
+
+import "math"
+
+// Signbit returns true if x is negative or negative zero.
+func Signbit(x float32) bool {
+	return math.Float32bits(x)&(1<<31) != 0
+}