Add GitHub action to run tests

Author: JakeSidSmith

.github/workflows/test.yml

@@ -0,0 +1,28 @@
+name: Tests
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version-file: '.nvmrc'
+      - name: Get npm cache directory
+        id: npm-cache-dir
+        run: |
+          echo "::set-output name=dir::$(npm config get cache)"
+      - uses: actions/cache@v3
+        id: npm-cache # use this to check for `cache-hit` ==> if: steps.npm-cache.outputs.cache-hit != 'true'
+        with:
+          path: ${{ steps.npm-cache-dir.outputs.dir }}
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
+      - run: npm ci
+      - run: npm test