Implement graceful-config

[yidafu]

Usage

Read config.{default|NODE_ENV}.{js|json} in specific directory,

const config = new GracefulConfig({
  path: './config/',
  prefix: 'matrix',
});

const value = config.getConfig('foo[0][1].bar[1]');

// all config value has been freezen， you can't modify any config values
value.baz = 'modify'; // doesn't work

Merge 2 GracefulConfig Instance.

const config1 = new GracefulConfig({
  path: './path/to/dir-1/config/',
  prefix: 'matrix',
});

const config2 = new GracefulConfig({
  path: './path/to/dir-2/config/',
  prefix: 'matrix',
});

config1.merge(config2)

Learn more about usage, pleace see test/ directory.