Adding postgres driver for native build

Author: javieraviles

.github/workflows/master.yml

@@ -15,7 +15,7 @@ jobs:
       with:
         java-version: 11
     - name: Build native with Maven
-      run: mvn -B package -Pnative -Dquarkus.native.container-build=true
+      run: mvn -B package -Pnative -Dquarkus.native.container-build=true -Dquarkus.datasource.driver=org.postgresql.Driver
     - name: Upload target for next job
       uses: actions/upload-artifact@v1
       with:
@@ -63,4 +63,4 @@ jobs:
     - uses: matt-ball/newman-action@master
       with:
         collection: integrationtests/quarkus-github-flow.postman_collection.json
-        environment: integrationtests/env/quarkus-github-flow-test.postman_environment.json
+        environment: integrationtests/env/quarkus-github-flow-test.postman_environment.json