function rank( data, opts, clbk ) {
	if ( arguments.length < 3 ) {
		// Assume `opts` arg is the callback...
		return factory( {}, opts )( data );
	}
	factory( opts, clbk )( data );
}
Ranks users provided user detail data.

@param {ObjectArray} data - user detail data
@param {Object} [opts] - function options
@param {string} [opts.token] - GitHub access token
@param {string} [opts.useragent] - user agent string
@param {string} [opts.method="followers"] - rank method
@param {Function} clbk - callback to invoke upon completing analysis
@returns {void}