Switch to v3 of github.com/emicklei/go-restful

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

vendor/github.com/emicklei/go-restful/v3/log/log.go

@@ -0,0 +1,34 @@
+package log
+
+import (
+	stdlog "log"
+	"os"
+)
+
+// StdLogger corresponds to a minimal subset of the interface satisfied by stdlib log.Logger
+type StdLogger interface {
+	Print(v ...interface{})
+	Printf(format string, v ...interface{})
+}
+
+var Logger StdLogger
+
+func init() {
+	// default Logger
+	SetLogger(stdlog.New(os.Stderr, "[restful] ", stdlog.LstdFlags|stdlog.Lshortfile))
+}
+
+// SetLogger sets the logger for this package
+func SetLogger(customLogger StdLogger) {
+	Logger = customLogger
+}
+
+// Print delegates to the Logger
+func Print(v ...interface{}) {
+	Logger.Print(v...)
+}
+
+// Printf delegates to the Logger
+func Printf(format string, v ...interface{}) {
+	Logger.Printf(format, v...)
+}