CI maven workflow

Author: michele

.github/workflows/maven.yml

@@ -1,9 +1,25 @@
 name: Java CI
 
-on: [push]
+on:
+  pull_request:
+    branches:
+      - master
 
 jobs:
-  build:
+  package:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - name: Set up JDK 1.8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+      - name: Package
+        run: mvn --no-transfer-progress -DskipTests=true package
+
+  test:
 
     runs-on: ubuntu-latest
 
@@ -15,7 +31,9 @@ jobs:
           - docker.io/arangodb:3.5.0
           - docker.io/arangodb/enterprise:3.4.8
           - docker.io/arangodb/enterprise:3.5.0
-        topology:   [single, cluster]
+        topology:
+          - single
+          - cluster
 
     steps:
       - uses: actions/checkout@v1
@@ -29,5 +47,3 @@ jobs:
           ARANGO_LICENSE_KEY: ${{ secrets.ARANGO_LICENSE_KEY }}
       - name: Test
         run: mvn --no-transfer-progress test
-      - name: Package
-        run: mvn --no-transfer-progress -DskipTests=true package