convert $and operator alias to [Sequelize.Op.and] (#52)
convert $and operator alias to [Sequelize.Op.and] (#52)

* convert $and alias operator to [Sequelize.Op.and]

Operators alias are already deprecated in Sequelize 4 and it's already advised to run without it.

In Sequelize 5 they will be completely gone.

This change removes the $and operator and uses the future-proof syntax.

* support Sequelize 3.x which doesn't provide Op

mickhansen/dataloader-sequelize,jayprakash1/dataloader-sequelize