Switch to pnpm package manager (#4)

* Switch to pnpm

* Update CI to use pnpm

* Add node 20, remove 14 from test matrix

Author: IanVS

.github/workflows/test.yml

@@ -10,18 +10,22 @@ jobs:
     strategy:
       matrix:
         node-version:
+          - 20
           - 18
           - 16
-          - 14
     name: Node.js ${{ matrix.node-version }}
     steps:
       - name: Checkout the repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
+        # Pulls version from packageManager key in package.json
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v2
       - name: Install Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v2
+        uses: actions/setup-node@v3
         with:
           node-version: ${{ matrix.node-version }}
+          cache: "pnpm"
       - name: Install dependencies
-        uses: bahmutov/npm-install@v1
+        run: pnpm install
       - name: Run unit tests
-        run: npm test
+        run: pnpm test