function isNotBlacklisted( pkg ) {
		if ( !blacklist ) {
			return true;
		}
		if ( contains( blacklist, pkg ) ) {
			return false;
		}
		return true;
	}
Checks whether a package appears in the list of blacklisted package names.

@private
@param {string} pkg - package name
@returns {boolean} boolean indicating whether a package is blacklisted