Vendor in latest containers/image

Adds support for credential helpers

Signed-off-by: umohnani8 <umohnani@redhat.com>

vendor/github.com/docker/docker-credential-helpers/osxkeychain/url_non_go18.go

@@ -0,0 +1,41 @@
+//+build !go1.8
+
+package osxkeychain
+
+import (
+	"net/url"
+	"strings"
+)
+
+func getHostname(u *url.URL) string {
+	return stripPort(u.Host)
+}
+
+func getPort(u *url.URL) string {
+	return portOnly(u.Host)
+}
+
+func stripPort(hostport string) string {
+	colon := strings.IndexByte(hostport, ':')
+	if colon == -1 {
+		return hostport
+	}
+	if i := strings.IndexByte(hostport, ']'); i != -1 {
+		return strings.TrimPrefix(hostport[:i], "[")
+	}
+	return hostport[:colon]
+}
+
+func portOnly(hostport string) string {
+	colon := strings.IndexByte(hostport, ':')
+	if colon == -1 {
+		return ""
+	}
+	if i := strings.Index(hostport, "]:"); i != -1 {
+		return hostport[i+len("]:"):]
+	}
+	if strings.Contains(hostport, "]") {
+		return ""
+	}
+	return hostport[colon+len(":"):]
+}