code: function sync(schemas) {
    var resolver = new Resolver(schemas);
    // Reduce force sequential execution.
    return Promise.resolve(Promise.reduce(resolver.resolve(), syncSchema.bind(this), []))
    .tap(function () {
      var knex = this.knex;
      return Promise.map(schemas || [], function(schema) {
        return (schema.postBuild || _.noop)(knex);
      });
    }.bind(this));
  }
docs: Synchronize given schemas with database. If it exists, it calls `postBuild` afterwards
  
  @param {[Schemas]} schemas
  @return {Promise}