Auth phase 2 - add DB

[cawak]

In brief:

• We are going to use PostgreSql because we may have many to one or many to many relations, and it's easier to handle role / permissions relations.
• We are going to have only uuids.
• Design the entities - we will have to have 3 tables:

1. User:

   userUuid
   email (string)
   full name
   encrypted password (string)
   roleUuid
   create_time_stamp
   update_time

2. Role:

   uuid
   role (string)

3. Role per permission (many to many):

   roleUuid
   permissionUuid

4. Permission:

   uuid
   permissionName

We need to check whether we can unite tables 2-4 into a single one which will resemble table 3.

Additional user data which related to business may be related to the soon to come recommendation module.