function path( opts ) {
	var search = '?';
	if ( opts.query ) {
		search += opts.query;
		search += '&';
	}
	search += 'page=' + opts.page;
	search += '&';
	search += 'per_page=' + opts.per_page;
	return opts.pathname + search;
}
Returns a resource path (pathname + search).

@private
@param {Options} opts - function options
@param {string} opts.pathname - resource pathname
@param {PositiveInteger} opts.page - resource page
@param {PositiveInteger} opts.per_page - page size
@param {string} opts.query - params portion of a query string
@returns {string} resource path