Updates go-cleanhttp to get better tuning for newer Go versions.

vendor/github.com/hashicorp/go-cleanhttp/cleanhttp.go

@@ -3,6 +3,7 @@ package cleanhttp
 import (
 	"net"
 	"net/http"
+	"runtime"
 	"time"
 )
 
@@ -22,13 +23,15 @@ func DefaultTransport() *http.Transport {
 func DefaultPooledTransport() *http.Transport {
 	transport := &http.Transport{
 		Proxy: http.ProxyFromEnvironment,
-		Dial: (&net.Dialer{
+		DialContext: (&net.Dialer{
 			Timeout:   30 * time.Second,
 			KeepAlive: 30 * time.Second,
-		}).Dial,
-		TLSHandshakeTimeout: 10 * time.Second,
-		DisableKeepAlives:   false,
-		MaxIdleConnsPerHost: 1,
+		}).DialContext,
+		MaxIdleConns:          100,
+		IdleConnTimeout:       90 * time.Second,
+		TLSHandshakeTimeout:   10 * time.Second,
+		ExpectContinueTimeout: 1 * time.Second,
+		MaxIdleConnsPerHost:   runtime.GOMAXPROCS(0) + 1,
 	}
 	return transport
 }

vendor/vendor.json

@@ -438,10 +438,10 @@
 			"revisionTime": "2015-10-22T18:15:14Z"
 		},
 		{
-			"checksumSHA1": "Uzyon2091lmwacNsl1hCytjhHtg=",
+			"checksumSHA1": "6ihdHMkDfFx/rJ1A36com2F6bQk=",
 			"path": "github.com/hashicorp/go-cleanhttp",
-			"revision": "ad28ea4487f05916463e2423a55166280e8254b5",
-			"revisionTime": "2016-04-07T17:41:26Z"
+			"revision": "a45970658e51fea2c41445ff0f7e07106d007617",
+			"revisionTime": "2017-02-11T00:33:01Z"
 		},
 		{
 			"checksumSHA1": "jPxyofQxI1PRPq6LPc6VlcRn5fI=",