Remove setupDB method and all tests that depend on it.

[dannyprikaz]

Overview

Tests that depend on the setupDB method from /backend/setup-test.js are failing intermittently, it seems because a MongoMemoryServer is being setup and inconsistently reset. We need to remove this method and all tests that depend on it to avoid inconsistent tests.

Action Items

• Remove all references to setupDB
• Remove all tests that depend on setupDB
• Remove setupDB method from /backend/setup-test.js