Add missing pack install

Author: jvalkeal

.github/workflows/ci.yml

@@ -12,6 +12,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
+    - name: Install pack
+      uses: jvalkeal/[email protected]
+      with:
+        pack-version: 0.18.0
     # cache maven repo
     - uses: actions/cache@v1
       with: