ci: ensure java 1.8

Java 1.6 cannot download the Adobe libraries due to a SSL cert issue

Author: developher-net

.github/workflows/run-tests.yml

@@ -25,6 +25,17 @@ jobs:
       uses: actions/setup-node@v2
       with:
         node-version: ${{ matrix.node-version }}
+    - uses: actions/setup-java@v1
+      with:
+        java-version: 11
+    # Set up dependency cache
+    - name: Cache local Maven repository
+      uses: actions/cache@v2
+      with:
+        path: ~/.m2/repository
+        key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
+        restore-keys: |
+          ${{ runner.os }}-maven-
     - run: npm ci
     - run: npm run build --if-present
     - run: npm test