Add cache to workflow

Author: usulpro

.github/workflows/npmpublish.yml

@@ -12,6 +12,11 @@ jobs:
       - uses: actions/setup-node@v1
         with:
           node-version: 12
+      - name: Cache node modules
+        uses: actions/cache@v1
+        with:
+          path: node_modules
+          key: dependencies
       - run: yarn
       - run: yarn test
       - run: yarn prepare