fix(logrotate): Now creates dir needed

If the directory containing the target log file doesn't exist, try and
create the directory first

logrotate/logrotate.go

@@ -4,6 +4,7 @@ package logrotate
 
 import (
 	"os"
+	"path"
 	"sync"
 	"time"
 )
@@ -54,6 +55,13 @@ func (w *RotateWriter) Rotate() (err error) {
 	}
 
 	// Create a file.
+	dir := path.Dir(w.filename)
+	_, err = os.Stat(dir)
+	if err != nil {
+		if err = os.Mkdir(dir, os.ModeDir); err != nil {
+			return
+		}
+	}
 	w.fp, err = os.Create(w.filename)
 	return
 }