Update node-js-ci workflow to fix broken npm installs

.github/workflows/node-js-ci.yml

@@ -11,31 +11,17 @@ on:
 jobs:
   build:
     runs-on: ${{matrix.os}}
-
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        node-version: [12.x, 14.x, 15.x]
+        node-version: [12.x, 14.x]
 
+    name: Node ${{ matrix.node_version }} on ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v2
-      - name: Cache node modules
-        uses: actions/cache@v2
-        env:
-          cache-name: cache-node-modules
-        with:
-          # npm cache files are stored in `~/.npm` on Linux/macOS
-          path: ~/.npm
-          key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/package.json') }}
-          restore-keys: |
-            ${{ runner.os }}-build-${{ env.cache-name }}-
-            ${{ runner.os }}-build-
-            ${{ runner.os }}-
-
       - name: Test
-        uses: actions/setup-node@v1
+        uses: actions/setup-node@v2.1.5
         with:
           node-version: ${{ matrix.node-version }}
-
       - run: npm install
       - run: npm test