migrate localeIdentifier field in Parse _Installation to new format

migrator.js

Parse.Cloud.job("localeIdentifierMigration", function(request, status) {
	var modify = function(old) {
		return old.replace(/_/g, "-").split("@")[0];
	};
  Parse.Cloud.useMasterKey();
  var query = new Parse.Query("_Installation");
  query.each(function(installation) {
			var old = installation.get("localeIdentifier");
			if (old) {
				installation.set("localeIdentifier", modify(old));
			}
      return installation.save();
  }).then(function() {
    status.success("Migration completed successfully.");
  }, function(error) {
    status.error("Something went wrong.");
  });
});