Vendor update with github.com/ugorji/go and github.com/apache/thrift pinning (#1805)

This fix is an vendor update. Both ugorji and thrift have to be pinned
to compile. The ugorji is from etcd and thrift is from zipkin.

This fix fixes #1802.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

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])
 	}