use dep as denpendency managment tool

vendor/gopkg.in/inf.v0/dec.go

@@ -104,7 +104,7 @@ var bigInt = [...]*big.Int{
 
 var exp10cache [64]big.Int = func() [64]big.Int {
 	e10, e10i := [64]big.Int{}, bigInt[1]
-	for i, _ := range e10 {
+	for i := range e10 {
 		e10[i].Set(e10i)
 		e10i = new(big.Int).Mul(e10i, bigInt[10])
 	}