function Mocha(options) {
  options = options || {};
  this.files = [];
  this.options = options;
  this.suite = new exports.Suite('', new exports.Context);
  this.ui(options.ui);
  this.reporter(options.reporter);
  if (options.timeout) this.suite.timeout(options.timeout);
}
Setup mocha with `options`.

Options:

  - `ui` name "bdd", "tdd", "exports" etc
  - `reporter` reporter instance, defaults to `mocha.reporters.Dot`
  - `globals` array of accepted globals
  - `timeout` timeout in milliseconds
  - `ignoreLeaks` ignore global leaks

@param {Object} options
@api public