Tran/users admin

[tnt07-t]

Overview

Added admin authorization and an isAdmin field to the Users model. Also removed legacy GitHub-related routes and models, including services listing functionality.

Changes Made

• added isAdmin to the Users model
• added requireAdmin middleware
• restricted GET /users to admin users only
• removed serviceslisting and other legacy Hustle routes/models

Test Coverage

Tested locally.

• normal user requesting GET /users returns the expected error
• admin user requesting GET /users successfully receives all users

Next Steps

• Make admin-creation route (admin-protected)

[JoshD94]

lgtm