code: function (connectionName, collectionName, relations, cb) {
  
        var connectionObject = connections[connectionName];
        if (!connectionObject) return cb(Errors.InvalidConnection);
  
        async.series(
          [
            // drop the main table
            function(cb) {
  
              var collection = connectionObject.collections[collectionName];
              if (!collection) return cb(Errors.CollectionNotRegistered);
  
              collection.dropTable(function(err) {
                // ignore "table does not exist" error
                if (err && err.code === 8704) return cb();
                if (err) return cb(err);
                cb();
              });
            },
  
            // drop relations
            function(cb) {
              // do it in parallel
              async.eachSeries(relations,
                function(item, cb) {
  
                  var collection = connectionObject.collections[item];
                  if (!collection) return cb(Errors.CollectionNotRegistered);
  
                  collection.dropTable(function(err) {
                    // ignore "table does not exist" error
                    if (err && err.code === 8704) return cb();
                    if (err) return cb(err);
                    cb();
                  });
                },
                function(err, results) {
                  if (err) return cb(err);
                  cb();
                }
              );
            }
          ],
          function(err, results) {
            if (err) return cb(err);
            cb();
          }
        );
      }
docs: Drop
  
  Drop a table
  
  @param {String} connectionName
  @param {String} collectionName
  @param {Array} relations
  @param {Function} cb