Add internal/util/files.go

internal/util/files.go

@@ -0,0 +1,18 @@
+package util
+
+import "os"
+
+// RemoveFileIfExists removes filename if exists, or does nothing if the file
+// is not there. Returns an error, if it occurred during deletion.
+func RemoveFileIfExists(filename string) error {
+	_, err := os.Stat(filename)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			return err
+		}
+		// no db file
+		return nil
+	}
+
+	return os.Remove(filename)
+}