Add mem free printing (I need it to verify a suspicion relating to a bug)

node_modules/lv_font_conv/lib/writers/bin.js

@@ -0,0 +1,17 @@
+// Write font in binary format
+'use strict';
+
+
+const AppError = require('../app_error');
+const Font     = require('../font/font');
+
+
+module.exports = function write_images(args, fontData) {
+  if (!args.output) throw new AppError('Output is required for "bin" writer');
+
+  const font = new Font(fontData, args);
+
+  return {
+    [args.output]: font.toBin()
+  };
+};