Reverted Dockerfile change (wasn't intended to push)
diff --git a/Dockerfile b/Dockerfile
index a7598d4..a10b5d8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -15,7 +15,7 @@
 # specific language governing permissions and limitations
 # under the License.
 
-FROM maven:3.5-jdk-9-slim
+FROM maven:3.5-jdk-8-alpine
 
 # Set data directory used for the app's persistence
 VOLUME /data