message: Check the result of webpack command
diff: @@ -56,6 +56,7 @@ describe('KintonePlugin', () => {
  ['--config', 'webpack.config.customize.name.js', ...webpackOptions],
  { cwd: pluginDir }
  );
  + assert(rs.error == null, rs.error && rs.error.message);
  verifyPluginZip(customNamePluginZipPath);
  });
  });
  