Reformat the give processedUpdates array to an object format that is expected by the sync client
@param {Array} processedUpdates the array of updates to process
@returns {Object} an object that contains the updates with different types
function formatUpdates(processedUpdates) {
  var updates = {
    hashes: {}
  };
  _.each(processedUpdates, function(update) {
    var type = update.type;
    var hash = update.hash;
    updates.hashes[hash] = update;
    updates[type] = updates[type] || {};
    updates[type][hash] = update;
  });
  return updates;
}