Update GitLab Pipeline to match GitHub Actions #202
Description
The GitLab pipeline should lint, build, and test the code across the same permutations as the GitHub Actions:
- Node.js 14.x with Mongo 4.0
- Node.js 14.x with Mongo 4.2
- Node.js 16.x with Mongo 4.0
- Node.js 16.x with Mongo 4.2