Updating go-checkpoint lib to have a fixed timeout

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

@@ -18,6 +18,7 @@ import (
 	"path/filepath"
 	"reflect"
 	"runtime"
+	"strconv"
 	"strings"
 	"time"
 
@@ -204,6 +205,12 @@ func Check(p *CheckParams) (*CheckResponse, error) {
 		return &CheckResponse{}, nil
 	}
 
+	// set a default timeout of 3 sec for the check request (in milliseconds)
+	timeout := 3000
+	if _, err := strconv.Atoi(os.Getenv("CHECKPOINT_TIMEOUT")); err == nil {
+		timeout, _ = strconv.Atoi(os.Getenv("CHECKPOINT_TIMEOUT"))
+	}
+
 	// If we have a cached result, then use that
 	if r, err := checkCache(p.Version, p.CacheFile, p.CacheDuration); err != nil {
 		return nil, err
@@ -250,6 +257,11 @@ func Check(p *CheckParams) (*CheckResponse, error) {
 	req.Header.Add("User-Agent", "HashiCorp/go-checkpoint")
 
 	client := cleanhttp.DefaultClient()
+
+	// We use a short timeout since checking for new versions is not critical
+	// enough to block on if checkpoint is broken/slow.
+	client.Timeout = time.Duration(timeout) * time.Millisecond
+
 	resp, err := client.Do(req)
 	if err != nil {
 		return nil, err

vendor/vendor.json

@@ -769,10 +769,10 @@
 			"revision": "7554cd9344cec97297fa6649b055a8c98c2a1e55"
 		},
 		{
-			"checksumSHA1": "vnuMNXv3FJSg/I8ig04OTEHjk1c=",
+			"checksumSHA1": "D267IUMW2rcb+vNe3QU+xhfSrgY=",
 			"path": "github.com/hashicorp/go-checkpoint",
-			"revision": "a8d0786e7fa88adb6b3bcaa341a99af7f9740671",
-			"revisionTime": "2017-06-24T02:34:07Z"
+			"revision": "1545e56e46dec3bba264e41fde2c1e2aa65b5dd4",
+			"revisionTime": "2017-10-09T17:35:28Z"
 		},
 		{
 			"checksumSHA1": "fSe5y1UgTDeYlnFfUcDA1zzcw+U=",