ci: improve release.yml

- Format the code to have empty lines separating conceptual blocks;
- Upgrade from ubuntu-18.04 to ubuntu-latest;
- Upgrade from actions/checkout@v1 to actions/checkout@v2;
- Set Node.js version from 12 to 12.x;
- Add step to handle node_modules caching;

Author: gustavopch

.github/workflows/release.yml

@@ -1,18 +1,34 @@
 name: Release
+
 on: push
+
+env:
+  CI: true
+
 jobs:
   release:
-    name: Release
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
+
     steps:
       - name: Checkout
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2
+
       - name: Setup Node.js
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 12.x
+
+      - name: Use cached node_modules
+        uses: actions/cache@v1
+        with:
+          path: node_modules
+          key: ${{ runner.os }}-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}
+
       - name: Install dependencies
         run: yarn --frozen-lockfile
+
       - name: Release
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}