Set up an Express server and a Postgres server running.

Express will be using Sequelize to connect to Postgres.

In Postgres, there will need to be a `Users` table with these column names and their DataTypes:

Column Name | DataType
-----|----
username | STRING
password | STRING
created_at | DATE
updated_at | DATE

```
$ sequelize init
$ sequelize model:create
$ sequelize help
```