Tests not run on PRs

[ljones140]

There's no tests run on this repository to prevent PRs being merged.

So we should put some tests in and ensure they are run before on PRs to master and on releases of the NPM package to GitHub packages

Will probably look like this action I asked Copilot to make

name: Node.js CI

on:
  push:
    branches: [ master ]
  pull_request:
    branches: [ master ]

jobs:
  build:
    runs-on: ubuntu-latest

    strategy:
      matrix:
        node-version: [14.x, 16.x]

    steps:
    - uses: actions/checkout@v2
    - name: Use Node.js ${{ matrix.node-version }}
      uses: actions/setup-node@v2
      with:
        node-version: ${{ matrix.node-version }}
    - run: npm install
    - run: npm test