Write tests for User API Endpoint

[tmthecoder]

Write Tests for User API Endpoint

Context

The User API endpoint exposes a set of publicly accessible API endpoints that allows callers to perform operations with users. We want to add e2e tests that checks the API endpoints function correctly

Requirements & Criteria

• Tests are written within api-gateway/tests/app.e2e-spec.ts
• Tests cover cases of invalid input (with appropriate exception/error checking)
• Tests cover cases of correct input
• Tests cover all API endpoints (get, link project, create, set type)

NOTE: The full test-suite for any package can be run in the root directory of the project by running yarn test:e2e:[service-name]