Sequelize 5 Warning

[jimmylee]

(node:19304) [SEQUELIZE0003]
DeprecationWarning: String based operators are deprecated. 
Please use Symbol based operators for better security, 
read more at 

http://docs.sequelizejs.com/manual/querying.html#operators

[jimmylee]

We don't need to have the operatorAliases property in our config because we don't use it.

Reference: sequelize/sequelize#8417 (comment)