ci: cache node_modules to speed up builds

.github/workflows/pull-request.yml

@@ -12,6 +12,18 @@ jobs:
       with:
         node-version: 12
 
+    - name: Cache node modules
+      uses: actions/cache@v2
+      env:
+        cache-name: cache-polymer-2
+      with:
+        path: ~/.npm
+        key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/package-lock.json') }}
+        restore-keys: |
+          ${{ runner.os }}-build-${{ env.cache-name }}-
+          ${{ runner.os }}-build-
+          ${{ runner.os }}-
+
     - name: Install CLI tools
       run: npm install -g bower polymer-cli web-component-tester
 
@@ -43,6 +55,18 @@ jobs:
       with:
         node-version: 12
 
+    - name: Cache node modules
+      uses: actions/cache@v2
+      env:
+        cache-name: cache-polymer-3
+      with:
+        path: ~/.npm
+        key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/package-lock.json') }}
+        restore-keys: |
+          ${{ runner.os }}-build-${{ env.cache-name }}-
+          ${{ runner.os }}-build-
+          ${{ runner.os }}-
+
     - name: Install CLI tools
       run: npm install -g bower magi-cli polymer-modulizer web-component-tester yarn
 

.gitignore

@@ -1,6 +1,5 @@
 bower_components
 node_modules
-package-lock.json
 yarn.lock
 coverage
 analysis.json