code: function Lookup(options) {
    this.options = options || {};
    this.cwd = this.options.cwd || process.cwd();
    this.limit = this.options.limit || 25;
    this.versions = {};
    this.history = {};
    this.parents = {};
    this.cache = {};
    this._paths = [];
    this.init(options);
  }
docs: Create a new instance of `Lookup`.
  
  ```js
  var Lookup = require('lookup-deps');
  var deps = new Lookup();
  ```
  
  @param {Object} `config` Optionally pass a default config object instead of `package.json`
  For now there is no reason to do this.
  @param {Object} `options`
  @api public