add ability to start zookeeper and kafka using docker-compose

- easing testability (especially for admin subproject, which requires both a running zookeeper and a running kafka instance). Embedded subproject just relies on a running zookeeper.
- necessary to run tests on travis

.travis.yml

@@ -8,8 +8,7 @@ services:
 before_install:
 - docker pull wurstmeister/zookeeper
 - docker pull wurstmeister/kafka
-- docker run -d -p 127.0.0.1:2181:2181 wurstmeister/zookeeper
-- docker run -d -p 127.0.0.1:9092:9092 wurstmeister/kafka
+- docker-compose up -d
 - docker ps -a
 
 jdk:

docker-compose.yml

@@ -0,0 +1,14 @@
+version: "2"
+services:
+  zookeeper:
+    image: wurstmeister/zookeeper
+    ports:
+        - "2181:2181"
+  kafka:
+    image: wurstmeister/kafka
+    ports:
+        - "9092:9092"
+    environment:
+        - "KAFKA_ZOOKEEPER_CONNECT=zookeeper:2181"
+        - "KAFKA_ADVERTISED_PORT=9092"
+        - "KAFKA_ADVERTISED_HOST_NAME=127.0.0.1"